---
title: "3.A: Do with rbioapi: Enrichment (Over-Representation) Analysis in R"
author: "Moosa Rezwani"
description: >
 Enrichment (Over-Representation) Analysis in R. Perform enrichment analysis using Enrichr, miEAA, PANTHER, Reactome, and STRING with rbioapi package.
date: "`r Sys.Date()`"
output:
  rmarkdown::html_vignette:
    toc: true
    anchor_sections: true
    number_sections: true
    self_contained: true
    dev: png
    encoding: 'UTF-8'
vignette: >
  %\VignetteIndexEntry{3.A: Do with rbioapi: Enrichment (Over-Representation) Analysis in R}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE, setup, echo=FALSE, results="hide"}
knitr::opts_chunk$set(echo = TRUE,
                      eval = TRUE,
                      message = FALSE,
                      warning = FALSE,
                      collapse = TRUE,
                      tidy = FALSE,
                      cache = FALSE,
                      dev = "png",
                      comment = "#>")
library(rbioapi)
rba_options(timeout = 600, skip_error = TRUE)
```

Among the databases and web services currently supported by rbioapi [Enrichr](https://maayanlab.cloud/Enrichr/ "Enrichr"), [miEAA](https://ccb-compute2.cs.uni-saarland.de/mieaa2 "miRNA Enrichment Analysis and Annotation Tool (miEAA)"), [PANTHER](http://www.pantherdb.org "Protein Analysis THrough Evolutionary Relationships (PANTHER)"), [Reactome](https://reactome.org/), and [STRING](https://string-db.org/ "STRING: Protein-Protein Interaction Networks Functional Enrichment Analysis") offer Enrichment (Over-Representation) analysis API endpoints. In this article, after a brief introduction, we will demonstrate how to perform Enrichment (Over-Representation) analysis in R, consistently and easily, using the package rbioapi.

Before continuing, note that rbioapi is an interface to the databases and web services. Hence it is the user's responsibility to cite the services they have used. We provide suggested citations in each function's manual. However, it is the user's responsibility to fully and adequately cite the databases or web services used in their published research.

------------------------------------------------------------------------

# How to install? {#how-to-install .heading2}

You can install the stable release version of [rbioapi](rbioapi.html "rbioapi: User-Friendly R Interface to Biologic Web Services' API") from [CRAN](https://cran.r-project.org/package=rbioapi "rbioapi page on CRAN (The Comprehensive R Archive Network)") with:

```{r install_cran, eval=FALSE}
install.packages("rbioapi")
```

However, the CRAN version is released at most once every 1-2 months, You can install the most recent (development) version from [GitHub](https://github.com/moosa-r/rbioapi/ "rbioapi repository on GitHub") with:

```{r install_github, eval=FALSE}
install.packages("remotes")
remotes::install_github("moosa-r/rbioapi")
```

------------------------------------------------------------------------

# What is Over-representation analysis? {#what-is-over-representation-analysis .heading2}

Enrichment (Over-Representation) analysis is commonly performed when one's analysis yields a list of genes, proteins, or other entities. We will not delve into details here and refer you to [D. W. Huang et al.: Nucleic Acids Res. 37, 1 (2009)](https://doi.org/10.1093/nar/gkn923 "Bioinformatics enrichment tools: paths toward the comprehensive functional analysis of large gene lists") for a thorough review of the subject.

In short, to perform such analysis, in addition to some algorithms, two data are required:

1) A gene list which is derived from your analysis.

2) Gene sets, where genes are grouped based on a shared property or concept (such as pathway, role in diseases, physical location, etc.).

With over-representation analysis, you can compare your gene list to find if the member of any gene set are over-represented, meaning that they are present in your list in a manner that can not be explained by chance alone.

# Enrichment (Over-Representation) analysis in R with rbioapi {#enrichment-analysis-in-R-with-rbioapi .heading2}

Many web services supported by rbioapi provide tools to perform over-representation analysis against the gene sets curated in their databases. Among the databases and web services currently supported by rbioapi, [Enrichr](https://maayanlab.cloud/Enrichr/ "Enrichr"), [miEAA](https://ccb-compute2.cs.uni-saarland.de/mieaa2 "miRNA Enrichment Analysis and Annotation Tool (miEAA)"), [PANTHER](http://www.pantherdb.org "Protein Analysis THrough Evolutionary Relationships (PANTHER)"), [Reactome](https://reactome.org/), and [STRING](https://string-db.org/ "STRING: Protein-Protein Interaction Networks Functional Enrichment Analysis") provide such services. Each service has a dedicated vignette article in rbioapi. Here we will focus on performing Enrichment (Over-Representation) analysis.

As a demonstration, we will use the results of [Galani et al.: Nat. Immunol. 22, 32 (2021)](https://doi.org/10.1038/s41590-020-00840-x "Untuned antiviral immunity in COVID-19 revealed by temporal type I/III interferon patterns and flu comparison") where they have compared the gene expression of critically ill and non-critically ill COVID patients to healthy individuals. We assign a variable with 1214 differentially expressed genes (DEGs) exclusively induced in critically ill COVID patients. Next, we will see what insights we can extract from this list.

```{r define var, echo=TRUE, message=TRUE}
covid_critical <- c("TXNDC5", "GABRR2", "MGAM2", "LOC200772", "LYPD2", "IFI27", "RPH3A", "OTOF", "NBPF8", "CLEC4F", "CNGB1", "HIST1H2BF", "HIF1A", "SDC1", "TUBB8", "FBXO39", "TPSB2", "CD177", "LRRN3", "EBLN2", "PCSK9", "ELK2AP", "UCHL1", "C22orf15", "LPO", "C3orf20", "CLRN1-AS1", "GPR75", "CA12", "RAB19", "CHRFAM7A", "CRYGN", "DLGAP5", "BTBD8", "LOC100272216", "PRG3", "CYP46A1", "LOC102723604", "PPAP2B", "C4BPA", "SPESP1", "LILRP2", "UBE2Q1-AS1", "MIR3945", "NOMO3", "MEG3", "LOC400927-CSNK1E", "MIR6732", "MIR590", "PPP1R3G", "PYCR1", "ARHGAP42", "MMP8", "HMMR", "P3H2", "ACER1", "NOG", "RAB39A", "ANTXRLP1", "LINC00266-3", "GPRC5D", "MCM10", "TSPY26P", "ANKRD36BP1", "GBP1P1", "PRL", "CYP1A1", "KIF4A", "LOC102724323", "SERPINB10", "GSTA4", "TRIM51", "MIXL1", "RNASE1", "CASC8", "MAOA", "XCL1", "ADAMTS2", "LOC101929125", "DCANP1", "BHLHA15", "ANOS1", "SLC18A1", "CCDC150", "CAV1", "SH3BP5", "LINC00398", "NCOA2", "SPATC1", "SHROOM2", "GPR27", "LRRC26", "RNF169", "USP3-AS1", "VWA7", "ROCK2", "FSTL4", "METTL7B", "CYP4F29P", "LEF1-AS1", "HORMAD2-AS1", "FBXO15", "PPTC7", "TYMS", "PPP4R2", "ZNF608", "FAM46B", "PCSK1N", "LINC00623", "CASC5", "ZNF224", "DENND2C", "WDR86", "PTGR1", "SPATA3-AS1", "LOC101927412", "KIF14", "MMP28", "PBK", "VMO1", "ADCY3", "HIST1H2BO", "FTO-IT1", "MIR342", "FANK1", "CRIP2", "TIAF1", "LOC344887", "OLFM4", "MKNK1-AS1", "ZDHHC19", "SEPT14", "EPSTI1", "FOXC1", "MIR616", "KRT72", "LINC01347", "LOC101928100", "KIAA0895", "BOK", "HIST1H2AI", "DBH-AS1", "ADORA2A-AS1", "MED12L", "SAMD15", "TARM1", "SMTNL1", "POU5F1P3", "LINC00968", "OAS3", "LOC103091866", "SH3RF3-AS1", "NBPF10", "APAF1", "SLC2A14", "SYT17", "ETV3", "SHROOM4", "AOAH-IT1", "NAIP", "ALAS2", "GLIS3", "ADAM17", "OLFM1", "PCAT29", "TNFRSF18", "DNASE1L3", "IGF2BP3", "LINC01271", "AP3B2", "TXNDC2", "CEP55", "SIGLEC1", "RAB3IL1", "PLD4", "KIFC1", "LINC00487", "ABHD12B", "ITGA7", "GJB6", "CARD14", "LRRN2", "MPO", "KLRC3", "LOC100507487", "SCGB3A1", "CD38", "LRRN1", "SYCP2L", "ANLN", "ASPM", "OAS1", "IFI44L", "CDCA3", "HLA-DQB2", "ANO9", "NUDT11", "HMP19", "DEPDC1", "GPR84", "PLEKHF1", "PI16", "RDH5", "TMED8", "LINC00824", "SEPT4", "CLIC3", "B4GALNT3", "OLAH", "ITGA1", "FOXI1", "LOC100506142", "CDC20", "HAGHL", "GTSCR1", "B3GALNT1", "SOCS3", "PCDH1", "TAS2R20", "CDC25A", "NPDC1", "LOC100505915", "XCL2", "TIAM2", "LOC100288069", "IL34", "IL18R1", "CYYR1", "ZNF888", "FAM20A", "MDS2", "ABCA13", "KCNJ1", "SLC4A9", "EXO1", "LAIR2", "IQSEC3", "SCT", "SLC26A8", "ESCO2", "ZDHHC1", "SNORA63", "FBLN5", "PRUNE2", "CPNE7", "CDHR2", "GNLY", "APOBEC3B", "MFSD9", "SYNGR3", "PTGDS", "COL17A1", "TBC1D14", "AIM2", "TMEM204", "FAM157B", "ZBED6", "EME1", "ATF3", "KBTBD4", "LUC7L2", "KIF20A", "LCNL1", "DOCK9-AS2", "KCNE1", "BTN2A3P", "KL", "IDI2-AS1", "EBF4", "SCARNA21", "CEACAM6", "KLRB1", "C5orf58", "ASXL2", "RPLP0P2", "CYTL1", "DIAPH3", "DOK7", "RFFL", "KIAA1107", "TAS2R40", "CCDC186", "COL6A2", "METRN", "SNHG25", "RRM2", "CYP1B1", "NEURL1", "MATK", "SLC28A3", "JCHAIN", "TNFRSF4", "FXYD1", "PLLP", "ARHGAP23", "SNORA4", "MYO18A", "ZNF429", "NRN1", "HJURP", "TCN1", "CDC6", "ATP5EP2", "SOAT2", "LOC101928034", "EIF2AK2", "ARG1", "SLC16A11", "TPPP3", "TMEM38A", "TOP2A", "LINC00999", "DGCR9", "RCAN3AS", "CACNG6", "LINC01550", "TDRD9", "CARD17", "GBP6", "LY6E", "RSAD2", "LOC100506258", "PRKAR2A", "LTF", "IGLL5", "FAM157A", "LOC101927018", "CCR7", "FLJ42351", "IFIT3", "GPRIN1", "ANXA9", "TMEM119", "PARGP1", "A3GALT2", "CYP4F22", "PLBD1-AS1", "SELM", "NCR3", "PNPLA1", "BMX", "LOC440461", "GAMT", "CEACAM8", "TP53I13", "C1orf226", "SKA3", "DHRS3", "VRK2", "BTBD19", "ETNK2", "LOC728323", "NRIR", "ADORA2A", "GPR162", "CMPK2", "USP18", "P4HA2", "TSSK4", "EP300", "CLEC4D", "LCN10", "GPR141", "SH2D2A", "GOLGA7B", "TMIGD2", "DLL4", "HP", "CXCR6", "MAL", "C12orf57", "CLIC5", "IL4", "IGFBP6", "ERG", "HERC3", "KEL", "MSX2P1", "INE1", "PRKCQ-AS1", "FHIT", "SLC1A7", "KIAA1958", "SARDH", "PFKFB3", "SNORD89", "IFI44", "DDX60", "TMEM238", "HAR1A", "EGR1", "VNN1", "TRIM9", "TAF13", "AP3S2", "TMEM56", "KLRC2", "CACNA1C-AS2", "ALX3", "FCGBP", "CD247", "ALDH1L2", "HIST1H2AC", "RTP5", "PPARG", "AMPH", "LINC00861", "CDKL5", "MYBL2", "LOC101927051", "TLR5", "TMEM121", "BMP8B", "AK5", "RBP5", "LINC01355", "PITRM1-AS1", "CMTM1", "BIRC5", "C10orf10", "TNFRSF25", "ZAP70", "LOC105373383", "DSP", "WDR86-AS1", "RPLP2", "KREMEN1", "LOC101927550", "PDZD4", "LOC100130451", "MKI67", "LOC728743", "CXCL10", "LINC01547", "LOC645513", "ATOH8", "S1PR5", "KISS1R", "MELK", "TCEA3", "SLC22A20", "RAMP1", "FOLR2", "GGT6", "CACNA1E", "FABP6", "RAP2C-AS1", "PRRG4", "FAM63B", "BLK", "P3H3", "WIPF2", "TROAP", "FAHD2CP", "CA6", "LINC00892", "LRCH3", "BUB1B", "LOC100996286", "NT5E", "PASK", "BATF2", "TTC39C-AS1", "ACTA2", "CHIT1", "LAMC1", "TNFAIP3", "ANKRD22", "C12orf42", "SPON2", "SLX4IP", "TNNC1", "ZNF771", "SPEG", "HIST1H4H", "HTR6", "TNFRSF17", "FSD1", "LINC00266-1", "CD6", "PRSS30P", "SFTPD", "COPZ2", "BPI", "CCIN", "CDK1", "ATP2C2", "GOLGA8H", "USP44", "SLC14A1", "ZDHHC14", "SNORD50A", "LTK", "KCNG2", "MAPK11", "ACOT4", "CTSW", "C1orf106", "CDKN3", "UPB1", "CAMK2N1", "RBM5-AS1", "DNLZ", "GZMM", "PLA2G7", "ZCCHC2", "PRSS41", "RPL13", "OLR1", "BCAS4", "EPB41", "TRABD2A", "PBX4", "GZMK", "PNPLA7", "B4GALT5", "ARHGEF17", "APOA1", "GPA33", "KLRG1", "GBP5", "LOC102723701", "CENPA", "LOC285696", "KCNK5", "SUSD4", "RPS28", "ESPL1", "ITGB4", "SPAG16", "CYP4F35P", "CD3D", "BMS1P20", "CBS", "ETV2", "SPATS2L", "DUSP13", "FAM19A1", "VSIG10L", "CD2", "NHSL2", "FAAH2", "FXYD7", "NTN5", "FICD", "GLDC", "LOC101927865", "LINC00944", "PTPRCAP", "GNB3", "TRIM22", "PRRT1", "NR1I3", "BTN3A1", "STX16-NPEPL1", "TMEM191A", "SERPINB2", "UST", "GALNT12", "BUB1", "GTF2I", "FOSL2", "COL13A1", "RGS9", "NCALD", "DNAH10", "CA11", "CKB", "HSPB1", "CDC45", "ATP7B", "WNT5B", "ZNF699", "PRRT4", "GALNT14", "ZNF319", "DNAH17", "LOC283710", "CPEB4", "LY6G6C", "PPAN", "WASH5P", "HIST1H3H", "IL32", "TEPP", "CNR1", "YJEFN3", "FAM159A", "FGFBP2", "FKBP5", "BIN1", "VPREB3", "E2F8", "HK3", "CDH2", "HFE", "BEAN1-AS1", "KIFC3", "HELB", "HLA-DPB1", "GZMH", "LMNB1", "CC2D2A", "IQCH-AS1", "CTSF", "TMEM132D", "LEF1", "REL", "CBR3", "WNT10B", "LOC100289473", "APBA2", "KIF23", "LOC646471", "PNMA6A", "EPC2", "HBEGF", "S100B", "C14orf132", "KCND1", "SIPA1L2", "NCAPG", "OAS2", "C3AR1", "CSF1", "CHCHD6", "AUTS2", "IL24", "CDC42EP2", "LTBP3", "PXT1", "ADAMTS10", "BLZF1", "TPST1", "ID3", "GYG1", "EFCAB2", "MYO10", "TLE2", "SLC30A1", "CCNI", "WNT7A", "RBL2", "ERICH6-AS1", "IGFBP3", "DTL", "SORBS3", "RPS19", "SMA4", "RPS27", "BEAN1", "MIRLET7BHG", "ABCA1", "ZKSCAN7", "GPR34", "GPR153", "TRIM52", "GRASP", "RNASE2", "CENPF", "ACTG1P20", "MMP9", "ZFP82", "RTN1", "RPS21", "PCBP1-AS1", "PVRL3", "RPS10", "FER1L4", "SEPT1", "DEPDC1B", "LINC00926", "SEC14L2", "LOC100420587", "PCSK4", "HPS3", "KIR3DL1", "SPRN", "HRH2", "FAHD2B", "P3H4", "TMEM160", "ENGASE", "RAD51AP1", "ZNF233", "RAP1GAP", "TTBK2", "PINK1", "SH2D1B", "BAIAP2L1", "BECN1", "RPL13A", "INHBB", "HPCAL4", "TPM2", "ACVR2B", "CEP126", "RPL18", "B3GNT7", "ROBO3", "MYOM2", "SLC51A", "CCL5", "PROSER3", "RPL18A", "SERINC4", "ATP11B", "SMARCD3", "STMN3", "FAM173A", "CDK5RAP2", "GGH", "EIF4G3", "C18orf32", "SHCBP1", "CCM2L", "LAT", "PRF1", "ARL15", "WHAMMP1", "NBN", "ARHGEF11", "ZWINT", "BTBD11", "MCOLN2", "EYS", "GRAP", "TAP1", "FAM157C", "ANXA3", "MCEMP1", "TCF7", "IGSF9B", "SDSL", "LNPEP", "NSUN5P1", "FAM110B", "SPNS3", "ACTL10", "GCSAM", "LOC101927482", "UGCG", "CD24", "SCO2", "GMCL1", "SAMD12", "NUSAP1", "WNT1", "NME3", "LOC728084", "RGS18", "PNMA3", "KLRF1", "ENO2", "SUPT3H", "ATP5D", "ZC3H13", "PSTPIP2", "SNORD81", "SESN2", "TK1", "LHFPL2", "SCARNA10", "SERPING1", "SYT2", "SNORA33", "JAK2", "CYB5D1", "SH3RF3", "ARL14EP", "UBASH3A", "ARL5B", "SPRED2", "NELL2", "PPP2R2B", "CDH12", "WDR54", "KLF4", "MTUS1", "ELF1", "CARNS1", "CLEC10A", "CD3E", "TTK", "KBTBD7", "TPX2", "ZNF69", "AICDA", "TAMM41", "LOC100288152", "AK1", "MMP24", "SAMD9L", "RAD51", "ACE", "COLGALT2", "NEDD4", "SPEF2", "CENPE", "CRISPLD2", "TSEN54", "RCVRN", "FRMD3", "SKAP1", "CYP4F3", "TMEM161B-AS1", "KANSL1L", "SLC29A2", "CEP97", "XAF1", "CDKN1C", "PRDM5", "HBP1", "CACNG8", "RP2", "OASL", "NPIPA1", "ZNF354A", "RPL32", "GLTSCR2", "CD52", "SBK1", "ZNF703", "GBP1", "C4orf29", "ERV3-1", "ABCC2", "EPB41L5", "FFAR3", "PLEKHB1", "LOC100507387", "RPL36", "PRC1", "C19orf60", "PRSS23", "CD160", "HOPX", "SAMD10", "RPSAP9", "CDCA2", "SWT1", "NPEPL1", "RORC", "MS4A3", "BCL2L15", "CXCR5", "EPHX2", "B3GNT9", "CDCA7L", "LMTK2", "UBAP1L", "CD79B", "OBSCN", "TMEM102", "ZNF540", "SPP1", "HABP4", "LOC100130872", "APBB1", "GPC2", "CD1C", "LONRF3", "NR2C2", "NSUN7", "SIGIRR", "SNORD38B", "FAM65C", "HELZ2", "ARL4D", "ENO3", "RPL9", "IFT81", "LSMEM2", "SCARNA2", "CD5", "AHNAK2", "RPL27A", "SOX8", "TMEM161A", "ZNF81", "PXK", "LOC441081", "RPS26", "CCNB1", "PLXDC1", "NFKBIA", "PKMYT1", "SLC27A5", "LRRC4", "TARP", "MAP2K6", "EIF1B-AS1", "SCARNA17", "NUDT8", "EAF1", "TBC1D8", "SESTD1", "CLEC12B", "ZNF776", "PDCD1", "FBXL16", "SLFN14", "ATP8B3", "ZNF396", "STOM", "CCDC30", "FAM86FP", "FAM129C", "TMEM42", "ZNF607", "IL11RA", "ECHDC2", "CCNE2", "PUS7L", "EFCAB12", "TGFA", "MAPK14", "NSG1", "C9orf142", "KLHL15", "LOC102723766", "VEGFB", "TJP3", "YAE1D1", "PROS1", "CSGALNACT2", "HLA-DOA", "TUBBP5", "RPL37A", "FAM195A", "LTB4R2", "NCAPH", "EVL", "CR1", "LTC4S", "ANKS3", "RPL35", "GLIS2", "TRAPPC6A", "LIPN", "RPS12", "RPL38", "LIME1", "PHGDH", "C4orf48", "SLED1", "BACH2", "EVA1C", "GATA3", "SLC25A38", "USP32", "RPL39", "EGR2", "USP35", "ZNF662", "PLEKHG1", "CRTAM", "AANAT", "OPLAH", "FBXO6", "LOXL1", "LOC101928786", "FRMD4B", "IL1R1", "ADM2", "DNASE1L1", "STAT4", "RPLP1", "TTC9", "BEND7", "F8", "FOSB", "SLAMF6", "STK17B", "PVT1", "ARVCF", "APOBEC3C", "CDK14", "RPS14", "POLQ", "CDC42BPG", "CCDC85B", "UBR5-AS1", "TNNT3", "TCL1A", "IL7R", "PTX3", "KLHL14", "MTRNR2L1", "ZBTB46", "RPL34", "VPS9D1-AS1", "KLF7", "RPL10A", "SLC2A11", "ACTN4", "RPSA", "SGK223", "PLSCR1", "SBF2", "LINC01420", "CDCA5", "F5", "ADGRB2", "RPL23A", "MAN1A2", "LLGL2", "GINS2", "NUDT14", "TG", "RSRC1", "TMEM256", "SYTL2", "TYSND1", "TPGS1", "ABHD14B", "LSM7", "ZNF281", "CEMP1", "M1AP", "CD82", "LOC101928150", "MRPL41", "IFIH1", "CCNB2", "IFITM10", "RPS3A", "TMEM8B", "CEP135", "SIRPB2", "IRS2", "SYCE1L", "SULT1B1", "ADAM9", "ZCCHC18", "DDIAS", "LINC01278", "MTHFD2", "TIGIT", "FUOM", "FOSL1", "RPS16", "BRAF", "CACNA1I", "EXT1", "GPR82", "LRRC45", "STAG1", "KIF11", "NCAM1", "RNF24", "KIAA2018", "SAMD9", "ABCA2", "PVRIG", "RASGRF2", "IRAK2", "ARHGEF4", "ZNF682", "RASSF7", "THAP7", "KIF1B", "GAS5", "KIF15", "RMRP", "GALM", "LYNX1", "C7orf50", "ATXN1L", "KCNN4", "LDLRAP1", "RETSAT", "RNF10", "NOXA1", "UBXN7", "UHRF1BP1L", "TESPA1", "MB21D1", "LINC00116", "FOXM1", "CCR6", "NMUR1", "RPL22", "LCK", "MEGF9", "CLSPN", "MIR4697HG", "PPP1R15A", "ADCK5", "SAMD3", "RPS27A", "TPPP", "PIWIL4", "ANKRD33B", "IL18RAP", "SNRPD2", "WASF1", "ALDH5A1", "FAM149B1", "RPS18", "SLCO4C1", "MGC16275", "ZNF837", "SAMHD1", "NSMF", "PDIA6", "SNX20", "ATF7IP2", "BPHL", "RPL35A", "NFKBIZ", "LMF1", "MGMT", "PPL", "FAM120C", "APRT", "RANGRF", "PHLDB3", "IDNK", "RPS15", "LGR6", "MOB1A", "CREB5", "THEM4", "ENDOG", "RPL7", "EDN1", "ZNF808", "SNHG15", "RPL3", "SMCR8", "FCMR", "ZNF449", "ZBTB37", "NHLRC4", "DHRS9", "C1QTNF3", "MS4A1", "AFF2", "FBXO32", "SLC6A6", "ZSCAN30", "CHPT1", "PARP14", "MZT2B", "FLT3LG", "TCTN2", "MAN1A1", "LOC728175", "ALOX5", "DUSP18", "ZC3H12D", "PECR", "LRRC37A3", "EPB41L4A-AS1", "SPAG5", "KDM7A", "DDX31", "NCOA6", "SLC6A12", "FCER1A", "FBXL13", "AKR7A2", "PRR5", "PRKCE", "PPP1R3D", "SYNM", "GLI1", "NTNG2", "EEF1G", "LOC643802", "MAGEE1", "PIK3AP1", "RPS8", "SNHG19", "C19orf70", "GAS7", "PHF12", "ATP11A", "SLC22A23", "ATP6V0E2", "UCKL1-AS1", "TIPARP", "BEX2", "FAM102A", "RPS20", "TTC16", "PLP2", "HAPLN3", "C19orf24", "ZNF397", "FOXO4", "TRAPPC2B", "QTRT1", "CDK10", "PDZD8", "GIPC1", "CD274", "C9orf139", "SPIB", "KLHDC7B", "ZNF32", "ELMO2", "AK4", "SAMD4B", "MFSD3", "EXD3", "SLC37A3", "RPL8", "TRIM56", "NMB", "PIPOX", "PXN-AS1", "SLC2A5")


```

***Please Note**: Over-representation services return large responses. To reduce the size of this vignette article, we will only display the first 10 rows of each Data Frame.*

## Enrichr {#enrichr .heading2}

[Enrichr](https://maayanlab.cloud/Enrichr/ "Enrichr") , developed in the Ma'ayan Lab, is a service to perform enrichment analysis against a considerable number of curated gene set libraries across various species.

We have thoroughly covered performing enrichment analysis with Enrichr in the vignette article [Enrichr & rbioap](rbioapi_enrichr.html "2.A: Enrichr & rbioapi")[i](https://rbioapi.moosa-r.com/articles/rbioapi_enrichr.html "2.A: Enrichr & rbioapi"). Therefore, we will only provide a brief demonstration here.

First, let us retrieve a list of available libraries in Enrichr using the `rba_enrichr_libs()` function. You can find the available Enrichr libraries in the `libraryName` column in the returned data frame.

```{r enrichr_libs, echo=TRUE, message=TRUE}
enrichr_libs <- rba_enrichr_libs()
```

```{r enrichr_libs_df, echo=FALSE}
if (is.data.frame(enrichr_libs)) {
  DT::datatable(data = enrichr_libs,
                autoHideNavigation = TRUE,
              options = list(scrollX = TRUE, 
                             paging = TRUE,
                             fixedHeader = TRUE,
                             keys = TRUE,
                             pageLength = 10))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

While the only required argument of `rba_enrichr()` function is `gene_list`, here we use `gene_set_library` argument to request an enrichment analysis only against "KEGG_2021_Human" library.

```{r enrichr, echo=TRUE, message=TRUE}
enrichr_enrich <- rba_enrichr(gene_list = covid_critical,
                              gene_set_library = "KEGG_2021_Human")
```

```{r enrichr_df, echo=FALSE}
if (is.data.frame(enrichr_enrich)) {
  enrichr_enrich <- enrichr_enrich[order(enrichr_enrich$Adjusted.P.value),]
  enrichr_enrich <- enrichr_enrich[1:min(10,
                                         nrow(enrichr_enrich)),]
  DT::datatable(data = enrichr_enrich,
                autoHideNavigation = TRUE,
                options = list(scrollX = TRUE, 
                               paging = TRUE,
                               fixedHeader = TRUE,
                               keys = TRUE,
                               pageLength = 10
                ))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

In the `gene_set_library` parameter, you can also provide multiple gene set libraries or leave it as the default parameter `NULL` to perform the enrichment analysis using every gene set library available in Enrichr. Also note that when `regex_library_name` parameter is TRUE (the default value), `gene_set_library` parameter will be considered as a regex pattern, so partial matchs will be also selected.

```{r enrichr_multi_libs, echo=TRUE, message=TRUE}
enrichr_enrich_kegg <- rba_enrichr(gene_list = covid_critical,
                                   gene_set_library = "kegg",
                                   regex_library_name = TRUE # default value
)
```

As you can see below, when than one library is selected, the results will be a list where each of its elements is the enrichment results of one library:

```{r enrichr_multi_libs_str, echo=TRUE, message=TRUE}
str(enrichr_enrich_kegg, max.level = 2)
```

## Reactome Analysis services {#reactome-analysis-services .heading2}

Reactome curates extensive and top-quality cellular pathways data across various species. Given the fact that proteins operate in organized units, which are the pathways, analyzing your list against Reactome pathways gene sets can provide valuable insights into the functional trajectories of your results.

You can refer to [Reactome & rbioapi](rbioapi_enrichr.html "2.E: Reactome & rbioapi") article for in-depth coverage of Reactome services. Here we will only demonstrate the over-representation functionality

The function `rba_reactome_analysis()` accepts gene lists or a table as input. If a table is supplied, the first column should consist of identifiers, and the next column should be numerical gene expression values. Refer to `rba_reactome_analysis()` function's manual for details. Here, we will use our gene list of critical COVID:

```{r reactome, echo=TRUE, message=TRUE}
reactome <- rba_reactome_analysis(input = covid_critical)
```

Let us examine the response's structure:

```{r reactome_str, echo=TRUE, message=TRUE}
str(reactome, max.level	= 1)
```

The list's element names are self-explanatory. The results are returned as a data frame in the `pathways` element. Note that Reactome will map your provided gene identifiers and some identifiers may not be found. Hence, keep an eye on the `identifiersNotFound` element.

```{r reactome_df, echo=FALSE}
if (utils::hasName(reactome, "pathways") && is.data.frame(reactome$pathways)) {
  reactome$pathways <- reactome$pathways[1:min(10,
                                               nrow(reactome$pathways)),]
  DT::datatable(data = reactome$pathways,
                autoHideNavigation = TRUE,
                options = list(scrollX = TRUE, 
                               paging = TRUE,
                               fixedHeader = TRUE,
                               keys = TRUE,
                               pageLength = 10))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

Naturally, you can alter the analysis parameters using the `rba_reactome_analysis()` function's arguments. The used parameters are returned in the "summary" element.

```{r reactome_summary_dummy, echo=FALSE}
#### this is to prevent vignetee building failarue in case of service being down.
if(!is.list(reactome)) {
  reactome <- list(summary = list(token = "Vignette building failed. It is probably because the web service was down during the building."))
}
```

```{r reactome_summary, echo=TRUE, message=TRUE}
str(reactome$summary)
```

In the above code chunk, note the "token" associated with your analysis. You can use this token to perform the following.

Retrieve the analysis results:

```{r reactome_token, echo=TRUE, message=TRUE, eval=FALSE}
reactome_2 <- rba_reactome_analysis_token(reactome$summary$token)
```

In addition to the main response, you can download other data associated with your request. see the argument `request` in the `rba_reactome_analysis_download()` function's manual for more information. Here, we will download a CSV file with the input identifiers which has not been found:

```{r reactome_download, echo=TRUE, message=TRUE, eval=FALSE}
rba_reactome_analysis_download(token = reactome$summary$token,
                               request = "not_found_ids",
                               save_to = "my_analysis.csv")
```

Reactome also generates a nice report of your analysis in pdf format, make sure to try it:

```{r reactome_pdf, echo=TRUE, message=TRUE, eval=FALSE}
rba_reactome_analysis_pdf(token = reactome$summary$token,
                          species = 9606, #Homo sapiens
                          save_to = "my_analysis.pdf")
```

## PANTHER {#panther .heading2}

PANTHER (protein analysis through evolutionary relationships) is a project that provides classification systems of genes and proteins. PANTHER also provides an enrichment service. In fact, the enrichment tool available on the [Gene Ontology (GO) website](http://geneontology.org/ "Gene Ontology Resource - Unifying Biology") is powered by [PANTHER](http://pantherdb.org/). Just like the previous sections, we will only review the enrichment functionality here; for an in-depth review of PANTHER refer to the vignette article "[PANTHER & rbioapi](rbioapi_panther.html "2.D: PANTHER & rbioapi")".

To perform the analysis, first, we need to choose the classifications (i.e., gene sets) that we want to compare our results against it. To retrieve a list of available gene sets, we call the following function:

```{r panther_sets, echo=TRUE, message=TRUE}
panther_sets <- rba_panther_info(what = "datasets")
```

```{r panther_sets_df, echo=FALSE}
if (is.data.frame(panther_sets)) {
  panther_sets <- panther_sets[,-which(colnames(panther_sets) == "description")]
  DT::datatable(data = panther_sets,
                autoHideNavigation = TRUE,
                options = list(scrollX = TRUE, 
                               paging = TRUE,
                               fixedHeader = TRUE,
                               keys = TRUE,
                               pageLength = 10))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

The Gene Ontology (GO) project is one of the pinnacles of scientists' collective effort in bioinformatics. The GO Consortium provides a comprehensive model of biological systems. In short, GO curates a thoroughly designed directed acyclic graph (DAG) of ontologies. You may think of it as a tree of terms, where as it branches out, the terms become more specific). Each protein may be annotated with one or more terms. The terms are organized in three domains: "Molecular Function," "Biological Process," and "Cellular Component". GO slim datasets refer to subsets which are a cut-down version of GO terms. If you are not familiar with GO, I strongly encourage you to see this page and follow the links it provides: [About the GO resource](http://geneontology.org/docs/introduction-to-go-resource/ "About the GO resource").

Here, we demonstrate the enrichment analysis using the Biological Process domain:

```{r panther_enrich, echo=TRUE, message=TRUE}
panther_enrich <- rba_panther_enrich(genes = covid_critical,
                                     organism = 9606, #Homo sapiens
                                     annot_dataset = "GO:0008150" #Biological Process
                                     )
```

In addition to the enrichment results, PANTHER returns other useful information about your analysis. The names are self-explanatory:

```{r panther_enrich_str, echo=TRUE, message=TRUE}
str(panther_enrich)
```

The enrichment results are returned as a Data Frame with an element named result:

```{r panther_enrich_df, echo=FALSE}
if (utils::hasName(panther_enrich, "result") && is.data.frame(panther_enrich$result)) {
  panther_enrich$result <- panther_enrich$result[1:min(10,
                                                       nrow(panther_enrich$result)),]
  DT::datatable(data = panther_enrich$result,
                autoHideNavigation = TRUE,
                options = list(scrollX = TRUE, 
                               paging = TRUE,
                               fixedHeader = TRUE,
                               keys = TRUE,
                               pageLength = 10))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

## STRING {#string .heading2}

In addition to proteins interaction data, STRING also curates proteins/genes annotations and provides enrichment analysis services. You can perform the analysis against multiple gene sets. Some of the gene sets can be accessed using other services but two gene sets are exclusive to STRING. See "[D. Szklarczyk et al.: Nucleic Acids Res. 49, D1 (2021)](https://doi.org/10.1093/nar/gkaa1074 "The STRING database in 2021: customizable protein–protein networks, and functional characterization of user-uploaded gene/measurement sets")" for further information. Again. We will only review the enrichment functionality here; for an in-depth review of STRING refer to the vignette article "[STRING & rbioapi](rbioapi_string.html "2.F: STRING & rbioapi")".

-   Gene sets exclusively in STRING:

    1.  Reference Publications ([PubMed](https://pubmed.ncbi.nlm.nih.gov/))

    2.  [Hierarchical clustering of the STRING network](https://string-db.org/help/faq/#what-are-local-string-network-clusters "What are local STRING network clusters?")

-   Gene sets also available in other services:

    1.  [Gene Ontology](http://geneontology.org/ "Gene Ontology Resource - Unifying Biology") domains: Molecular Function, Biological Process, and Cellular Component

    2.  [COMPARTMENTS](https://academic.oup.com/database/article/doi/10.1093/database/bau012/2633793 "Subcellular localization database")

    3.  [Human Disease Ontology](https://disease-ontology.org/ "Disease Ontology")

    4.  [InterPro](https://www.ebi.ac.uk/interpro/ "Classification of protein families")

    5.  [KEG1G pathways](https://www.genome.jp/kegg/pathway.html "Wiring diagrams of molecular interactions, reactions and relations")

    6.  [UniProt keyword](https://www.uniprot.org/keywords/ "UniProt keyword: a controlled vocabulary with a hierarchical structure")

    7.  [Pfam](https://pfam.xfam.org/ "A large collection of protein families, each represented by multiple sequence alignments and hidden Markov models (HMMs)")

    8.  [Reactome pathways](https://reactome.org/PathwayBrowser/ "free, open-source, curated and peer-reviewed pathway database")

    9.  [BRENDA Tissue and Enzyme Source Ontology](https://bioportal.bioontology.org/ontologies/BTO/)

    10. [SMART](http://smart.embl-heidelberg.de/ "Genetically mobile domains and the analysis of domain architectures")

We can directly supply our `covid_critical` variable to STRING's enrichment function:

```{r string_enrich, echo=TRUE, message=TRUE}
string_enrich <- rba_string_enrichment(ids = covid_critical,
                                       species = 9606 #Homo sapiens
                                       )
```

As you can see, by default a list is returned where each element is a data Frame with enrichment analysis results against one of the gene sets listed above:

```{r string_str, echo=TRUE, message=TRUE}
str(string_enrich, max.level = 1)
```

In the "PMID" element, we see which PubMed papers are over-represented with our gene list. To keep the table tidy, we are not displaying the `inputGenes` and `preferredNames` columns.

```{r string_df, echo=FALSE}
if (utils::hasName(string_enrich, "PMID") && is.data.frame(string_enrich$PMID)) {
  string_enrich$PMID <- string_enrich$PMID[,                                           !colnames(string_enrich$PMID) %in% c("inputGenes", "preferredNames")]                                             
  string_enrich$PMID <- string_enrich$PMID[1:min(10, 
                                                 nrow(string_enrich$PMID)),]
  DT::datatable(data = string_enrich$PMID,
                autoHideNavigation = TRUE,
                options = list(scrollX = TRUE, 
                               paging = TRUE,
                               fixedHeader = TRUE,
                               keys = TRUE,
                               pageLength = 10))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

You can retrieve the annotations associated with your input protein(s). The difference here is that no statistical analysis will be performed and the full annotations of your input gene will be returned. Because of potentially unwieldy response, `allow_pubmed` is set fo FALSE by default. Here we set it to TRUE to also retrieve the PubMed paper abstracts that include our gene.

```{r string_annot, echo=TRUE, message=TRUE}
string_annot <- rba_string_annotations(ids = "CD177",
                                       species = 9606, #Homo sapiens
                                       allow_pubmed = TRUE
                                       )
```

As you can see, Our input gene has a large number of annotations. Let us take a look at the PMID Data Frame, which contains the PubMed Abstract paper terms:

```{r string_annot_str, echo=TRUE, message=TRUE}
str(string_annot, max.level = 1)
```

```{r string_annot_df, echo=FALSE}
if (utils::hasName(string_annot, "PMID") && is.data.frame(string_annot$PMID)) {
  string_annot$PMID <- string_annot$PMID[1:min(10, 
                                                 nrow(string_annot$PMID)),]
  DT::datatable(data = string_annot$PMID,
                autoHideNavigation = TRUE,
                options = list(scrollX = TRUE, 
                               paging = TRUE,
                               fixedHeader = TRUE,
                               keys = TRUE,
                               pageLength = 10))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

## miEAA {#mieaa .heading2}

The miRNA Enrichment Analysis and Annotation Tool ([miEAA](https://ccb-compute2.cs.uni-saarland.de/mieaa2/ "https://ccb-compute2.cs.uni-saarland.de/mieaa2")) is a service provided by the [Chair for Clinical Bioinformatics at Saarland University](https://www.ccb.uni-saarland.de/). What makes miEAA unique among other services presented here is that miEAA curates miRNA sets. Hence you can directly perform miRNA enrichment analysis across various species with the services miEAA provides.

We have in-depth covered performing enrichment analysis with miEAA in the vignette article "[miEEA & rbioapi](rbioapi_mieaa.html "2.C: miEEA & rbioapi")[i](https://rbioapi.moosa-r.com/articles/rbioapi_enrichr.html "2.A: Enrichr & rbioapi")". Therefore, we will only provide a brief demonstration here.

We can not use our `covid_critical` gene list here. We rather use a miRNA list from the paper "[A. Parray et al.: Vaccines 9, 1056 (2021)](https://doi.org/10.3390/vaccines9101056 "SnoRNAs and miRNAs Networks Underlying COVID-19 Disease Severity")". They used microarray to find differentially expressed miRNA in the severe versus mild COVID 19 patients' blood.

```{r input_mirs, echo=TRUE, message=TRUE}
covid_mirna <- c("hsa-miR-3609", "hsa-miR-199a-5p", "hsa-miR-139-5p", "hsa-miR-145-5p","hsa-miR-3651", "hsa-miR-1273h-3p", "hsa-miR-4632-5p","hsa-miR-6861-5p", "hsa-miR-6802-5p","hsa-miR-5196-5p","hsa-miR-92b-5p", "hsa-miR-6805-5p","hsa-miR-98-5p","hsa-miR-3185", "hsa-miR-572","hsa-miR-371b-5p","hsa-miR-3180", "hsa-miR-8073","hsa-miR-4750-5p","hsa-miR-6075", "hsa-let-7i-5p","hsa-miR-1231","hsa-miR-885-3p")
```

While not necessary, we can first see what enrichment categories are available for our mature human miRNA:

```{r mieaa_libs, echo=TRUE, message=TRUE}
rba_mieaa_cats(mirna_type = "mature",
               species = 9606 #Homo sapiens
)
```

Next, we will use the wrapper function available to perform the necessary steps in one function call. Note that we have supplied the categories parameter. If left NULL, the enrichment will be performed against every available category.

```{r mieaa, echo=TRUE, message=TRUE}
mieaa_enrich <- rba_mieaa_enrich(test_set = covid_mirna,
                                 mirna_type = "mature",
                                 test_type = "ORA",
                                 species = 9606,
                                 categories = "miRPathDB_GO_Biological_process_mature")
```

```{r mieaa_df, echo=FALSE}
if (is.data.frame(mieaa_enrich)) {
  mieaa_enrich <- mieaa_enrich[1:10,]
  DT::datatable(data = mieaa_enrich,
                autoHideNavigation = TRUE,
                options = list(scrollX = TRUE, 
                               paging = TRUE,
                               fixedHeader = TRUE,
                               keys = TRUE,
                               pageLength = 10
                ))
} else {
  print("Vignette building failed. It is probably because the web service was down during the building.")
}
```

------------------------------------------------------------------------

# How to cite? {#how-to-cite .heading2}

rbioapi is an interface between you and other databases and services. Thus, if you have used rbioapi in published research, kindly in addition to citing rbioapi, make sure to fully and properly cite the databases/services you have used. Suggested citations have been added in the functions' manuals, under the "references" section; Nevertheless, it is the user's responsibility to check for proper citations and to properly cite the database/services that they have used.

Please see the [rbioapi's main vignette article](rbioapi.html#how-to-cite) for more details.

------------------------------------------------------------------------

# Links {#links .heading2}

-   [This article in rbioapi documentation site](https://rbioapi.moosa-r.com/articles/rbioapi_do_enrich.html "Over-Representation Analysis with rbioapi")

-   [Functions references in rbioapi documentation site](https://rbioapi.moosa-r.com/reference/index.html "rbioapi reference")

-   [rbioapi vignette index](rbioapi.html "rbioapi: User-Friendly R Interface to Biologic Web Services' API")

------------------------------------------------------------------------

# Session info {#session-info .heading2}

```{r sessionInfo, echo=FALSE}
sessionInfo()
```
