Mice lacking MAIT cells are more susceptible to chronic colitis and inflammation-induced colorectal cancer, and MAIT cells obtained from models of chronic intestinal inflammation clustered due to common expression of the anti-inflammatory cytokine transforming growth factor-beta 1 (TGF-β1) and receptor cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). The gene discussed is TGFB1; the disease is colorectal cancer.