IFNG and tuberculosis: IFN-γ responses were more common in subjects with latent TB compared to those without TB (ESAT-6, 49.3% vs. 26.6%, P < 0.0001; Ag85, 38.6% vs. 24.8%, P < 0.0001; WCL, 78.4% vs. 42.8%, P < 0.0001), but IFN-γ responses were not consistently different between subjects with and without active TB (ESAT-6, 38.5% vs. 26.6%, P = 0.3366; Ag85, 23.1% vs. 24.8%, P = 0.8881; WCL, 76.9% vs. 42.8%, P = 0.0133).