IFIH1 and infection: The supportive role of MDA5 in primed macrophages for M. tuberculosis survival could be especially relevant during early infection, when IFN-γ levels are known to increase in bronchoalveolar lavage fluid, and M. tuberculosis–infected IFN-γ–primed alveolar macrophages (AMs) in the lung skew toward M1 polarization, which is less permissive for the growth of the pathogen (41).