TGFB1 and colorectal carcinoma: Interestingly, CRC cell lines used in such experiments are unresponsive to TGF-β1, and stimulation in vitro with TGF-β1 or anti-TGF-β1 did not impair the anti-proliferative effect of Smad7 AS in CRC cells, raising the possibility that Smad7 regulates CRC cell behavior through a TGF-β1-independent mechanism [94].