The latter defect is very similar to the strong decrease in acid-activated NHE3 activity observed in the surface colonocytes of the IL-10–deficient chronically inflamed colon in this study, as well as the decreased acid-activated NHE3 activity observed in surface colonocytes of moderately inflamed mucosa from ulcerative colitis patients [33], [40]. This evidence concerns the gene SLC9A3 and ulcerative colitis.