MADCAM1 and inflammatory bowel disease: The minor influence on AS reduction after anti-integrin (VDZ) therapy may be due to altering the binding of leukocyte α4ß7 integrin to the mucosal addressing cell adhesion molecule-1 (MAdCAM-1) expressed in high endothelial venules of the gut, inhibiting the migration of leukocytes to the intestinal tract (20,39) and VDZ may redirect trafficking of α4ß7-expressing lymphocytes to other systems, predisposing these patients to develop EIMs with a parallel course to IBD (20,40).