CD4 and tuberculosis: Strong correlations were observed between the frequency of CD153 (P < 0.0001; r = −0.53), IL‐2 (P < 0.0001; r = −0.67), CD27 (P = 0.0002; r = −0.43) and HLA‐DR (P = 0.0002; r = 0.45) expression by Mtb300‐specific IFNγ+ CD4 T cells and the PC1 loading score, indicative of TB disease extent (Figure 4a).