The areas under the curve (95% CI) for differentiating active pulmonary TB from other groups were 0.893 (0.864–0.924) for IFN-γ and 0.944 (0.922–0.965) for MIG, with corresponding sensitivities and specificities of 84.9% and 79.8% for IFN-γ and 92.5% and 85.2% for MIG, respectively. The gene discussed is CXCL9; the disease is pulmonary tuberculosis.