IL12RB1 and Mendelian susceptibility to mycobacterial diseases: Previous reports have shown that mutations in IL12RB1 impair Th1 differentiation and IFN-γ production in response to IL-12 and IL-23, resulting in MSMD and increased susceptibility to intracellular pathogens including Salmonella spp., but can also impair Th17 cell development and immunity to fungal pathogens such as Candida albicans26,40.