IFNG and tuberculosis: We examined the effect of anti-TB treatment on the frequencies of caspase-3 expressing Mtb-specific IFN-γ+CD4+ T cells in active TB patients and found that treatment-mediated resolution was associated with the decline of antigen-specific caspase-3+IFN-γ+CD4+ T cells which correlate with Mtb burden in vivo using sputum smear and culture measurement (Figures 6 and 7).