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. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Apr 2014].