In addition to its normal role in lymphocyte trafficking to mucosal lymphoid tissue, MAdCAM-1 expression is also dramatically increased in chronic inflammatory and disease states (33), e.g., inflammatory bowel disease (IBD) [2], sclerosing cholangitis, cirrhosis [12], and diabetes [13,14], and may play important roles in these conditions. The gene discussed is MADCAM1; the disease is inflammatory bowel disease.