IFNG and tuberculosis: The ROC analysis of the LTBI and TB compared to the CTRL provided an AUC of only 0.70 (95% IC: 0.55–0.84) for LTBI and of 0.81 (95% IC: 0.70–0.91) for TB (Fig. 1D), compared to 0.89 and 0.80, respectively, obtained for the PPD-induced IFN-γ secretions.