Hi, I just wonder what KEGG is for? I did GO enrichment analysis and found significant biological processes. Are these two analyses related? What can I know from the enrichKEGG?

Thanks

The KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway database contains pathway maps for cellular and organismal functions.

enrichKEGG() is a function which allows you to find overrepresented KEGG categories (pathways) in a set of significantly regulated genes. I would say it is complementary to a GO enrichment analysis. The main difference is that genes belonging to the same GO category do not necessarily have to be connected through a set of reactions, whereas KEGG categories are representations of (mostly) biological metabolic or signalling transduction pathways, in which the genes are connected through reactions. Also, the coverage of GO is larger than KEGG, because GO annotations are also 'electronically' annotated (IEA evidence; annotations that are computationally, or automatically, assigned to gene products without further manual curation), whereas KEGG categories are usually are manually curated.

Similar to KEGG are for example the Reactome Pathway Database, and WikiPwathways. There is large overlap between these databases.