TGFB1 and malignant colon neoplasm: Notably, TGF-β signaling is inactivated by mutation of TGFBR2/TGF-β receptor type II in around 30% of colon cancers or, less frequently, by that of the signal transducers SMAD2 or SMAD4, which limits the EMT-promoting role of TGF-β in this neoplasia.