Swine 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 involved in mucosal immune defense and leukocyte recruitment in pigs (Sus scrofa domesticus). 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 swine, CCL20 is produced by epithelial cells, macrophages, fibroblasts, and other immune cells in response to inflammatory stimuli such as microbial components, cytokines (e.g., IL-1β, TNF-α, and IL-17), and tissue injury. It is highly expressed at mucosal surfaces, particularly in the intestinal and respiratory epithelium, where it plays an important role in coordinating immune responses against pathogens. In swine health, CCL20 is especially relevant in enteric infections caused by pathogens such as Salmonella spp. and Escherichia coli, as well as in respiratory diseases including porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza, where epithelial production of CCL20 recruits antigen-presenting cells and lymphocytes to infected tissues. While CCL20-mediated immune cell trafficking supports pathogen clearance and mucosal immunity, excessive or prolonged expression can contribute to inflammatory tissue damage. Because pigs are widely used as large-animal models for human gastrointestinal and respiratory disease, characterization of swine CCL20 supports studies of mucosal immunity, chemokine-mediated immune cell migration, and development of improved vaccines and disease-control strategies in both veterinary and translational biomedical research.