Chemokine (C-C motif) ligand 20 (CCL20), or Macrophage Inflammatory Protein-3 (MIP3A), is a small cytokine belonging to the CC chemokine family. It is strongly chemotactic for lymphocytes and weakly attracts neutrophils. CCL20 is implicated in the formation and function of mucosal lymphoid tissues via chemoattraction of lymphocytes and dendritic cells towards the epithelial cells surrounding these tissues. CCL20 elicits its effects on its target cells by binding and activating the chemokine receptor CCR6.

CL20 expression was observed to be dependent on IL-6 amplifier activation, which is dependent on NF-κB and STAT3 activation. This research provides evidence for a critical role for CCL20 in autoimmune pathogenesis of the central nervous system.