TGFB1 and breast cancer: The clinical importance of this feedback loop is supported by a positive correlation between ZEB1/2 and TGF-β; by negative correlations between miR-200 and TGF-β and between miR-200 and ZEB1/2 in breast cancer [78,88]; and by an association between high miR-200 expression and better clinical outcomes in multiple cancer types [100].