Swine Interleukin-16 (IL-16) is a proinflammatory cytokine that plays an important role in regulating immune cell recruitment and activation in pigs (Sus scrofa). IL-16 is produced by several cell types, including CD8⁺ T cells, mast cells, eosinophils, and epithelial cells, in response to immune stimulation or inflammatory signals. Swine IL-16 functions primarily as a chemoattractant for CD4⁺ immune cells by binding to the CD4 receptor, promoting migration and activation of T helper cells, monocytes, and dendritic cells to sites of infection or inflammation. Through these actions, IL-16 contributes to coordination of immune responses and modulation of inflammatory signaling pathways. In pigs, IL-16 participates in immune responses against bacterial, viral, and parasitic pathogens and may influence inflammatory processes in tissues such as the respiratory and gastrointestinal tracts. Swine IL-16 is studied in veterinary immunology and infectious disease research, including investigations of immune responses to important swine pathogens such as porcine reproductive and respiratory syndrome virus (PRRSV), African swine fever virus (ASFV), and Salmonella spp., where IL-16–mediated immune cell recruitment contributes to regulation of inflammatory and host defense mechanisms.