Cynomolgus Monkey (Macaca fascicularis) CXCL9 (C-X-C motif chemokine ligand 9), also known as MIG (monokine induced by interferon-γ), is a proinflammatory chemokine belonging to the CXC chemokine family, which also includes CXCL10 (IP-10) and CXCL11 (I-TAC) that regulate T-cell recruitment during interferon-driven immune responses. In cynomolgus monkeys, CXCL9 is produced by macrophages, dendritic cells, endothelial cells, and epithelial cells in response to interferon-γ (IFN-γ) and inflammatory stimuli during infection or immune activation. CXCL9 signals primarily through the chemokine receptor CXCR3, which is expressed on activated T lymphocytes, natural killer (NK) cells, and other immune cells, promoting chemotaxis and accumulation of these cells at sites of infection or inflammation. Because cynomolgus monkeys share close genetic, immunological, and physiological similarities with humans, they are widely used as preclinical animal models for infectious diseases and immunological research. In these models, CXCL9 is part of the interferon-regulated chemokine network involved in antiviral immunity, including studies of SARS-CoV-2, dengue virus, and other viral infections, where CXCL9 contributes to CXCR3⁺ T-cell recruitment to infected tissues and regulation of inflammatory responses, making it an important marker of Th1-type immune activation in translational biomedical research.