In contrast, Mtb-specific CD4 T-cell responses of TB patients from SA were significantly enriched in IFN-γ+IL-2-TNF-α+IL-4/5/13- (dual IFN-γ/TNF-α Mtb-specific CD4 T cells) and in IFN-γ+IL-2-TNF-α-IL-4/5/13- CD4 T-cell populations (single IFN-γ Mtb-specific CD4 T cells) as compared to TB patients from TZ (about 45% versus 20–18% for dual IFN-γ/TNF-α and 25% versus 7–4% for single IFN-γ+; P<0.05) (Fig 1C). This evidence concerns the gene IFNG and tuberculosis.