Used in immunological research to quantify CXCL9 levels in biological samples such as serum, plasma, and cell culture supernatants. Helps assess immune activation, particularly in studies related to inflammatory diseases, autoimmune disorders, and cancer immunotherapy. Widely applied in clinical research to monitor disease progression and response to treatment by measuring chemokine expression linked to T-cell recruitment and macrophage activation. Suitable for investigating interferon-gamma-mediated responses and biomarker discovery in infectious diseases and chronic inflammation.