Feline 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 cats (Felis catus), CXCL9 is produced by macrophages, dendritic cells, endothelial cells, and epithelial cells in response to interferon-γ (IFN-γ) and other inflammatory cytokines during infection or immune activation. CXCL9 primarily signals 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. In feline health, CXCL9 contributes to cell-mediated immune responses against intracellular pathogens, including viral and protozoal infections, and plays a role in inflammatory processes affecting tissues such as the lung, skin, and lymphoid organs. Cats are also used as animal models for human viral and immunological diseases, particularly feline immunodeficiency virus (FIV) infection, which serves as a model for human HIV infection, where CXCL9 is part of the interferon-regulated chemokine network that directs T-cell trafficking and antiviral immune responses.