The expression and subcellular distribution of claudins differs in patients with intestinal inflammatory disease [14]; claudin-2, -5, -8 and claudin-2, -3, -5 expression is altered in the intestine of patients with Crohn's disease and celiac disease, respectively [44, 46], suggesting that claudin dysfunction may be an important symptom of these diseases. Here, CLDN2 is linked to celiac disease.