IFNGR1 and Mendelian susceptibility to mycobacterial diseases: Another well-described example can be found in Mendelian susceptibility of mycobacterial disease (MSMD), where patients with AR inherited IFNGR1 defects have a complete abrogated signal with an early-onset presentation, while patients with AD inherited defects can remain asymptomatic for a longer time because the mutation still allows for partially retained IFN-γ signaling activity (3).