the organism (default=NULL). Currently 'hs' (human), 'mm' (mouse) and 'dr' (zebrafish) are supported.
go2all.egs
mappings between a given GO identifier and all of the Entrez Gene identifiers
annotated at that GO term or to one of its child nodes in the GO ontology (default=NULL)
eg.alias2eg
mappings between common gene symbol identifiers and entrez gene identifiers (default=NULL)