IFNG and tuberculosis: There was, however, a clear differentiation between IFN-γ responses to the positive control condition (PHA) compared to medium in all subjects (83.2% vs. 18.6%, P < 0.0001), in subjects without TB (85.0% vs. 19.6%, P < 0.0001), in subjects with latent TB (79.7% vs. 16.9%, P < 0.0001), and in subjects with active TB (69.2% vs. 15.4%, P = 0.0028).