Using Rag−/− mice colitis model treated with IL-23R−/− CD45RBhigh and CD4+ cells alone were able to elevate IL-10 production, while co-transfer with wild-type T cells abrogated the action, implicating the capability of IL-23-responsive T cells to reduce IL-23R−/− T cells response and produce IL-10 in the colonic mucosa. This evidence concerns the gene IL23A and colitis.