Murine CCL9/10 is belonging to the CC chemokine family. It is encoded by the gene CCL9. MRP-2 (CCL9/10) was isolated from a murine macrophage cell line, RAW 264.7. MRP-2 shows a 51 % sequence identity at the protein level to MRP-1 (C10) and 46% identity to MIP-1-alpha (CCL3). The functional receptor for CCL9/10 has been identified as CCR1. In contrast, other CCR1 ligands, CCL3/MIP-1alpha and CCL5/RANTES are considered to be primary CCR1 ligands in inflammatory responses. CCL9 can activate osteoclasts suggesting an important role for it in bone resorption. Murine CCL9/10 is 75 % amino acid identical to rat CCL9/10.