Chemokine (C-C motif) ligand 7 (CCL7) is a small cytokine known as a chemokine that was previously called monocyte-specific chemokine 3 (MCP3). Due to CCL7 possessing two adjacent N-terminal cysteine residues in its mature protein, it is classified among the subfamily of chemokines known as CC chemokines. CCL7 specifically attracts monocytes, and regulates macrophagefunction. It is produced by certain tumor celllines and by macrophages. This chemokine is located on chromosome 17 in humans, in a large cluster containing many other CC chemokines and is most closely related to CCL2(previously called MCP1) .