IL7 and tuberculosis: As shown in Fig 3A, the TB antigen stimulated levels of IL-2 (GM of 1005 pg/ml in PTB versus 1184 pg/ml in LTB and 1204 pg/ml in NTB), IL-7 (GM of 15.49 pg/ml in PTB versus 37.33 pg/ml in LTB and 38.26 pg/ml in NTB) and IL-21 (GM of 76.15 pg/ml in PTB versus 319.3 pg/ml in LTB and 285.9 pg/ml in NTB), were significantly diminished in PTB compared to both LTB and NTB individuals.