ECRF3 is a virally encoded chemokine receptor found in the genome of herpesvirus saimiri (HVS), a primate-restricted T-lymphotropic gamma-herpesvirus that is closely related to Epstein-Ban virus (EBV). a human B-lymphotropic gamma-herpesvirus. ECRF3 is one of 14 open reading frames (ORFs) of HVS that lack homologs in EBV. and that have sequence homology with known cellular proteins. ECRF3 is 30% identical in deduced amino acid sequence to human CXCR2, its closest mammalian relative. Similar to CXCR2, the ligands for ECRF3 are IL-8, GROa, and NAP-2.