Chemokine (C-C motif) ligand 12 (CCL12) is a small cytokine belonging to the CC chemokine family that has been described in mice. It is also known as monocyte chemotactic protein 5 (MCP-5) and, due to its similarity with the human chemokine MCP-1, sometimes it is called MCP-1-related chemokine. CCL12 specifically attracts eosinophils, monocytes and lymphocytes.[1] This chemokine is found predominantly in lymph nodes and thymus under normal conditions, and its expression can be hugely induced in macrophages.[1] [2] It is thought to coordinate cell movements during early allergic reactions, and immune response to pathogens. The gene for CCL12 is found in a cluster of CC chemokines on mouse chromosome 11.[2]