It was found that MAIT cells are activated by C. difficile in an major histocompatibility complex class I-related protein (MR1)-dependent manner and in response produce IFN-γ, perforins, and granzyme B. In murine models IFN-γ is associated with protection against CDI as it presumably strengthens the immunological barrier of the gut (Abt et al., 2015; Bernal et al., 2018). This evidence concerns the gene IFNG and clostridium difficile infection.