ZEB1 and neoplasm: In addition, TGF-β has been shown to play paradoxical (tumor-initiating and tumor-suppressing) roles in cancer progression.13,14 Similarly, a poised chromatin configuration of ZEB1 promoter was shown to be tumorigenic, and ZEB1 can be both tumor-promoting and pro-apoptotic factors.14–16 These observations suggest that there are complex transcriptional programs activated by these two factors.