Chemokine ligand 20 (CCL20), also known as macrophage inflammatory protein 3α (MIP-3α), is a small molecular weight cytokine of the CC chemokine family.CCL20 has a strong chemotactic effect on lymphocytes and a weak chemotactic effect on neutrophils. Monocytes, macrophages, microglia, astrocytes, mast cells, keratinocytes, intestinal epithelial cells, osteoblasts, fibroblasts, endothelial cells, and bronchial epithelial cells express CCL20.CCL20 chemotaxis of lymphocytes and dendritic cells to epithelial cells surrounding mucosal lymphoid tissues and thus participates in the formation and functioning of mucosal lymphoid tissues.CCL20 CCL20 binds and activates the chemokine receptor CCR6 to act on target cells.CCL20 may play an important role in the pathogenesis of autoimmune diseases of the central nervous system.