This gene is one of several cytokine genes that are clustered on the q-arm of chromosome 17. Cytokines are a family of secreted proteins that function in inflammatory and immunoregulatory processes. The protein encoded by this family member is similar to the chemokine (C-C motif) ligand 4 product, which inhibits HIV entry by binding to the cellular receptor CCR5. The copy number of this gene varies among individuals, where most individuals have one to five copies. This gene copy contains a non-consensus splice acceptor site at the 3' terminal exon found in other highly similar gene copies, and it thus uses other alternative splice sites for the 3' terminal exon, resulting in multiple transcript variants. [provided by RefSeq, Apr 2014]