Snail is considered an effector of TGF-β-induced EMT and it is activated by TGF-β signaling through the action of p-Smad2/3 and Smad4 in mouse lens epithelial cells [49]; consistent with these reports, we also observed increased expression of Snail mRNA in K14E6 cataracts. This evidence concerns the gene SMAD4 and cataract.