IFNG and tuberculosis: Interferon-gamma (IFN-γ) release assays (IGRAs), such as the commercially available QuantiFERON-TB Gold In Tube (QFT-GIT, Cellestis, Ltd, Carnegie, Australia) and T-SPOT.TB tests (Oxford Immunotec Limited, Abingdon, United Kingdom), have the potential to overcome some of TST's limitations [6].