Current TB screening tests, such as the tuberculin skin test (TST) and the more specific interferon-gamma release assays (IGRAs), which measure CD4+ T cell responses to early secretary antigenic 6 kDa (ESAT-6) and culture filtrate protein 10 (CFP-10), have thus far not been shown to discriminate between persons with TB disease and TBI, nor to identify persons with recently acquired TBI (an important risk factor for progression to TB disease) (3). This evidence concerns the gene IFNG and tuberculosis.