note that this file lacks parent/child relations, so we only learn 'direct annotations'
go_gene2go(f, taxid_filter = 9606)
a tibble with columns; source, source_version, id, name, genes, ngenes
full path to gene2go file stored on the computer, e.g. previously downloaded from https://ftp.ncbi.nih.gov/gene/DATA/gene2go.gz
return gene annotations only for the specified taxonomy identifier (integer value). Typical options are 9606 (Human, the default) or 10090 (mouse). Importantly, select the taxonomy/organism that is also in your input gene list (which typically contains human Entrez gene identifiers)