IFNGR1 and Mendelian susceptibility to mycobacterial diseases: The downregulation of IFNγR1 in CD4+ and CD8+ T cells in NTM-PD patients supports the genetic findings of IFNγR1 deficiency in Mendelian Susceptibility Mycobacterial Disease (MSMD) patients, who are at high risk of NTM-PD (39).