IFNG and infection: Our previous study on intravenous cyclophosphamide therapy on active NTM infection patients with a high anti-IFN-γ autoantibody titer (range, 100,000–400,000 at the beginning) confirmed this finding, as patients with refractory infection had better outcomes when they had a decreased level of autoantibody titer (range, 1,000–10,000)25.