ZEB1 and breast cancer: The family of microRNAs 200 (miR-200a, miR-200b, miR-200c, miR-141 and miR-429) and the miR-205A regulate the expression of the transcriptional repressors of E-cadherin ZEB-1 and ZEB-2 and, consequently, the levels of E-cadherin in breast cancer cells and tissues.