CDH1 and cancer: Metformin's ability to enhance the epithelial behavior of cancer cells not only may occur through transcriptional inhibition of the “E-cadherin repressor interactome” (thus enhancing the expression of the metastasis suppressor protein E-cadherin at cell-cell junctions) but also by epigenetically preserving the differentiated phenotype of human epithelia via upregulation of the microRNA let-7a [38], a crucial regulator of CSC maintenance and point at connection between EMT and CSC formation [39].