Prepare gene sets for GSEA
prepare_gene_sets(pathway_type = "KEGG", organism = "ko", go_category = "all")A list of pathway gene sets
A character string specifying the pathway type: "KEGG", "MetaCyc", or "GO"
A character string specifying the organism (only relevant for KEGG and GO)
A character string specifying the GO category to use.
"all" (default) uses all categories. Valid values are determined by
the reference data; see table(ko_to_go_reference$category).