MR1 and inflammatory bowel disease: In a chronic model of chemically induced colitis, in which mice are subjected to repeated cycles of colitis induced by DSS to mimic the inflammatory flare typically observed in human inflammatory bowel diseases (IBD), Mr1−/− mice lose more weight and suffer worse epithelial damage than their Mr1+ cage mates (El Morr et al., 2024), indicating that the presence of MAIT cells is associated with reduced colitis severity in this setting.