CCL20 is an inflammatory cytokine involved in the recruitment of leukocytes to sites of injury and inflammation. CCL20 is expressed at a low basal level, but it is induced by proinflammatory cytokines and Toll-like receptor (TLR) agonists. During infections, CCL20 expression is stimulated in epithelial cells, and immature CCR6+ dendritic cells (DCs) are recruited. Thereafter, CCR6 is downregulated during DC maturation, and the DCs migrates to the lymph node under the expression of CCR7. CCL20 is the only ligand for CCR6. Nevertheless, mouse and human beta-defensin-1 and -2, small cationic antimicrobial peptides, bind and activate CCR6. Contrarily, these beta-defensins have lower affinities for CCR6 than CCL20. In fact, human CCL20 has potent antimicrobial activity.