SMAD7 and colorectal carcinoma: Since these findings are seen in CRC cells unresponsive to TGFβ1 and the anti-proliferative effect of Smad7 AS is not affected by stimulation of CRC cells with TGF-β1 or anti-TGF-β1, it is highly likely that Smad7 exerts pro-tumorigenic effects in a TGFβ1-independent manner (Figure 1) (97).