IFNG and tuberculosis: An increasing body of evidence, predominantly in immunocompetent adult populations, shows that IGRA (either whole blood based (for example, QuantiFERON-TB Gold assay) or enzyme-linked immunospot (IFN-γ ELISpot), (for example, T.SPOT.TB assay) have a similar sensitivity to that of the tuberculin skin test (TST) (between 70-90%) and a higher specificity for the detection of active TB disease [2].