SMAD7 and colorectal cancer: Guo et al. (2013) found that knockout of MLL2 in colorectal cancer cells could lead to altered expression of a variety of genes, including the decreased expression of Vimentin and increased expression of Smad7, which is the negative regulator of TGF-β/Smad signaling through blocking the phosphorylation of Smad2/3 (p-Smad2/3) (Luo et al. 2014).