Monocyte Chemotactic Protein 4 (MCP-4), also called CCL13, is induced by inflammatory Proteins such as IL-1 and TNF alpha. MCP-4 is a ligand for three different G Protein coupled receptors, CCR2, CCR3 and CCR5. MCP-4 activates signaling in monocytes, T lymphocytes, eosinophils and basophils and this signaling is associated with the allergic response. Recombinant MCP-4 is a non-glycosylated Protein, containing 74 amino acids, with a molecular weight of 8.5 kDa.