Mouse CCL20 (C-C motif chemokine ligand 20, also known as MIP-3α, macrophage inflammatory protein-3 alpha, or LARC – liver and activation-regulated chemokine) is a pro-inflammatory chemokine that plays an important role in mucosal immune defense and leukocyte recruitment in mice (Mus musculus). CCL20 signals specifically through the CCR6 receptor, promoting chemotaxis of immune cells including immature dendritic cells, memory T cells, Th17 cells, regulatory T cells, and certain B cell populations to sites of epithelial infection or inflammation. In murine systems, CCL20 is produced by epithelial cells, keratinocytes, fibroblasts, and immune cells in response to inflammatory cytokines such as IL-1β, TNF-α, and IL-17, as well as microbial stimulation. Mouse CCL20 is highly expressed in intestinal mucosa, skin, and respiratory epithelium, where it helps coordinate antigen presentation and adaptive immune activation. In research, CCL20 is widely studied in experimental models of inflammatory bowel disease, psoriasis-like skin inflammation, autoimmune encephalomyelitis (a model of multiple sclerosis), and respiratory infections, where CCR6–CCL20 signaling regulates recruitment of Th17 cells and dendritic cells to inflamed tissues. While CCL20-mediated immune cell trafficking supports pathogen defense and mucosal immunity, excessive or sustained expression can contribute to chronic inflammatory pathology. Because mice are the primary genetic model for studying immune regulation, characterization of mouse CCL20 has been essential for understanding Th17-mediated inflammation, mucosal immunity, and chemokine-driven leukocyte migration relevant to human autoimmune and inflammatory diseases.