Compared with vitamin A-supplemented mice, vitamin A-deficient mice had decreases in colonic subepithelial myofibroblasts and the ratio of mucosal IgA+/IgG+ cells, increases in CD11c+ dendritic cells, and a higher rate of development of colorectal carcinoma with colitis following azoxymethane. The gene discussed is ITGAX; the disease is colitis.