The median level of TB antigen-stimulated IFN-γ in the QFT-GIT test was significantly higher in the TPE group than in the MPE group (2.89 IU/mL vs 0.33 IU/mL; P<0.0001), whereas the levels of PHA-stimulated IFN-γ were comparable in both groups (P=0.6630) (Figure 2). This evidence concerns the gene IFNG and tuberculosis.