ZEB1 and neoplasm: It has been reported that TGF-β induces the expression of transcription factors such as Snail, Slug, Zeb, and Twist.10 Of these, Snail is greatly upregulated through the Smad pathway.36 During TGF-β-mediated EMT, the Snail-Smad3/4 transcriptional complex functions as a transcriptional repressor.37 HMGA2 and Smads bind to the Snail promoter and acquire the EMT phenotype.38 These compelling data suggest that Snail is regulated by TGF-β/Smad signaling from the tumor microenvironment.