IFNG and tuberculosis: This result was reaffirmed by subdividing those tested into three categories of QFT IFN-γ values (< 0.2 IU/mL, between 0.2 and 0.7 IU/mL, and > 0.7 IU/mL); the greater the IFN-γ response to TB specific antigens was, the less was their ability to inhibit mycobacterial growth (P = 0.0154).