tax_id
Taxon ID of the organism ("10090" for mouse, "10116" for rat, "4932" for S.Cerevisiae, "562" for E.Coli, "6239" for C.Elegans, "7227" for D.Melanogaster, "9606" for H.Sapiens, and "All" for all organisms). Default="All".
iref_version
iRefIndex distribution ("7.0", "8.0", "9.0", "10.0", "11.0", "12.0", "13.0" or "current"). Default="current".
data_folder
Folder to save the iRefIndex flat file: type "data" to save it in the "iRefR/data" directory, "home" to save it in the "R.home()" directory, or any other destination folder. Default=getwd().