Macrophage inflammatory protein-3 alpha (MIP-3 A), also called CCL20, is expressed in the liver, lungs, lymph nodes, and peripheral blood lymphocytes. MIP-3 A expression is strongly induced by inflammatory signals, and downregulated by the anti-inflammatory cytokine interleukin 10 (IL-10). MIP-3 A signals through the G protein-coupled receptor CCR6 to function as a chemoattractant to lymphocytes and dendritic cells.