Finally, PC1 of the measures of TB disease extent and PC1 of the Mtb‐specific IFNγ+ CD4 T cell phenotype at baseline showed strong correlation (P < 0.0001; r = −0.71), irrespective of HIV infection (P < 0.0001; r = −0.78 for HIV− and P < 0.0001; r = −0.67 for HIV+, data not shown; Figure 7a), indicating that, unlike the magnitude of Mtb‐specific CD4 response,32 the phenotypic characteristics of these cells associate with TB disease activity. The gene discussed is IFNG; the disease is tuberculosis.