The down-regulation of ZEB1 and ZEB2 increased E-cadherin expression; in contrast, loss of miR-200, which occurs in many different human cancers, including breast cancer [18], ovarian cancer [19], prostate cancer [20], and endometrial carcinoma [21], results in increased ZEB1/ZEB2 and repression of E-cadherin [16,22-24]. This evidence concerns the gene ZEB1 and breast cancer.