CD4 and tuberculosis: Further, caspase-3-expressing IFN-γ+CD4+ T cells were more activated compared to their caspase-3-negative counterparts and the frequencies of caspase-3+IFN-γ+CD4+ T cells decreased following successful anti-TB treatment, indicating that caspase-3 expression in Mtb-specific IFN-γ+CD4+ T cells is associated with mycobacterial burden.