Indeed, the SMAD7 mRNA can be rapidly induced up to 4–10 folds by TGFβ treatment in numerous types of cells30, 31; meanwhile, upregulation of SMAD7 to the same magnitude in mucosal mononuclear cells of inflammatory bowel disease patients as compared with the normal controls was sufficient to desensitize the cells to TGFβ (ref. 32). Here, SMAD7 is linked to inflammatory bowel disease.