Of the studies that have reported serial IGRA (whole blood or IFN-γ ELISpot assay) measurements prior to, during or at the completion of treatment of active TB disease in adults, four have shown an increase [23,24,29,30] and six a decrease [20,22,25-27,35] in the magnitude of the IFN-γ responses. Here, IFNG is linked to tuberculosis.