TGFB1 and colorectal carcinoma: However, TGF-β1-mediated Ras/Smad signaling [18-20] and contact with type I collagen mediated via α2β1 integrin [21] are believed to play a role in EMT in CRC, and αvβ6 has been suggested to be a marker of EMT in CRC and a prognostic factor for aggressive disease [22].