This gene encodes a member of the beta chemokine receptor family， which is predicted to be a seven transmembrane protein similar to G protein-coupled receptors. The ligands of this receptor include macrophage inflammatory protein 1 alpha (MIP-1 alpha)， regulated on activation normal T expressed and secreted protein (RANTES)， monocyte chemoattractant protein 3 (MCP-3)， and myeloid progenitor inhibitory factor-1 (MPIF-1). Chemokines and their receptors mediated signal transduction are critical for the recruitment of effector immune cells to the site of inflammation. Knockout studies of the mouse homolog suggested the roles of this gene in host protection from inflammatory response， and susceptibility to virus and parasite. This gene and other chemokine receptor genes， including CCR2， CCRL2， CCR3， CCR5 and CCXCR1， are found to form a gene cluster on chromosome 3p.