CDH1 and breast cancer: Best examples include the epithelial to mesenchymal transition (EMT) hallmark gene E-cadherin (CDH1), whose transcriptional silencing by hypermethylation occurs at high frequency in infiltrating primary breast cancers [44]; and Ras-related protein 17 (RAB17) gene coding for a small GTPase whose expression must be reduced for tumor cells to migrate efficiently [45] (Fig. 1F).