Background：This gene is a member of the human ADP-ribosylation factor （ARF） gene family. These genes encode small guanine nucleotide-binding proteins that stimulate the ADP-ribosyltransferase activity of cholera toxin and play a role in vesicular trafficking and as activators of phospholipase D. The gene products include 6 ARF proteins and 11 ARF-like proteins and constitute 1 family of the RAS superfamily. The ARF proteins are categorized as class I （ARF1, ARF2,and ARF3）, class II （ARF4 and ARF5） and class III （ARF6）. The members of each class share a common gene organization.
