MCP-5 （CCL12） is a cloned mouse CC chemokine most closely related to human MCP1 （66% amino acid sequence identity in the mature protein）. MCP5 is expressed constitutively in the thymus and the lymph nodes. Under inflammatory conditions， moreover CCL12 expression is induced in activated macrophages and mast cells. The mouse MCP1 gene is mapped to the CC chemokine cluster on chromosome 11. Recombinant CCL12 is a potent chemoattractant for monocytes and lymphocytes but not neutrophils. At high concentrations， MCP-5 also chemoattracts eosinophils. CCL12 is a functional ligand for CCR2.
