Notably, compared with Gpr15+/+ mice subjected to the same TNBS induction, Gpr15−/− mice presented alleviated symptoms of TNBS-induced colitis, including reduced body weight loss, a lower DAI, and colon shortening, as well as improved histopathology and colonoscopy scores (Fig. 3c, e, g and Supplementary Fig. 2a). The gene discussed is GPR15; the disease is colitis.