Chicken Interleukin-16 (IL-16) is a proinflammatory cytokine that plays an important role in regulating immune cell recruitment and activation in chickens (Gallus gallus). IL-16 is produced by several cell types, including T lymphocytes, epithelial cells, and other immune cells, in response to immune stimulation or inflammatory signals. Chicken IL-16 functions primarily as a chemoattractant for CD4⁺ immune cells by interacting with the CD4 receptor, promoting migration and activation of T helper cells, monocytes, and dendritic-like cells to sites of infection or inflammation. Through these actions, IL-16 contributes to coordination of cellular immune responses and regulation of inflammatory signaling pathways. In chickens, IL-16 participates in immune responses against viral, bacterial, and parasitic pathogens and may influence inflammatory processes in tissues such as the respiratory and gastrointestinal tracts. In cell culture, recombinant chicken IL-16 is used to study chemotactic responses of CD4⁺ immune cells, investigate mechanisms of immune cell recruitment and activation, and evaluate cytokine-mediated regulation of inflammatory pathways. Due to these functions, chicken IL-16 is studied in avian immunology and translational research, including investigations of host–pathogen interactions, vaccine responses, and immune regulation relevant to poultry health and disease resistance.