In order to determine how BTN and BTNL genes are regulated in intestinal inflammation and tumors, we used real‐time PCR to map the expression of human BTN and BTNL genes in patients with UC, irritable bowel syndrome (IBS) and colon cancer, and analyzed the presence of murine Btn and Btnl genes in mucin deficient mice (Muc2−/−), a mouse model that reflects clinical and cellular features of human ulcerative colitis 20, 21, and in ApcMin/+ mice, a spontaneous mouse model of intestinal cancerogenesis 22. The gene discussed is BTN1A1; the disease is irritable bowel syndrome.