Considering that patients who exhibit impaired immune responses related to the IL-12/IFN-γ axis or generate autoantibodies against IFN-γ frequently progress to being afflicted by severe disseminated and extrapulmonary forms of MAC disease, Th1-type immunity is regarded as a protective determinant of MAC disease responses [68–70]. This evidence concerns the gene IFNG and Mycobacterium avium complex disease.