Ferret 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 ferrets (Mustela putorius furo), CXCL9 is produced by macrophages, dendritic cells, endothelial cells, and epithelial cells in response to interferon-γ (IFN-γ) and inflammatory signals during infection or immune activation. CXCL9 signals primarily through the chemokine receptor CXCR3, 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 tissue inflammation. In ferret immunity, CXCL9 contributes to cell-mediated antiviral responses, particularly in the respiratory tract, where recruitment of CXCR3⁺ T cells supports clearance of viral infections. Ferrets are widely used as animal models for human respiratory viral diseases, including influenza virus and SARS-CoV-2, and CXCL9 is part of the interferon-regulated chemokine network that directs T-cell trafficking and antiviral immune responses in lung tissues. These studies make ferret CXCL9 important for understanding Th1-type immune responses and inflammatory signaling in respiratory infection models relevant to human disease.