IL21 and tuberculosis: In contrast, tuberculosis antigen–stimulated levels of IL-2 (GM of 1005 pg/ml in Pre-T versus 1197 pg/ml in Post-T), IL-7 (GM of 15.49 pg/ml in Pre-T versus 48.46 pg/ml in Post-T) and IL-21 (GM of 7615 pg/ml in Pre-T versus 319.3 pg/ml in Post-T) were significantly increased at post- treatment compared to pre-treatment levels in PTB individuals (Fig 3B).