IFNGR1 and infection: Interestingly, the same group demonstrated host protective effect of type I IFN in the lungs of Mtb-infected mice lacking IFN-γ signaling; the pulmonary bacterial loads were significantly higher in the Ifnar-/-/Ifngr-/- mice compared with that in the Ifngr−/− and Ifnar−/− mice on post-infection days 24 and 28 (211).