This analysis revealed that stable expression of miR-221 in MCF-7 cells resulted in small but significant reduction in E-cadherin mRNA levels of 20% (Fig. 2f), and downregulation of miR-221 in MDA-MB-231 cells resulted in E-cadherin mRNA slightly elevation (Fig. 2h), which indicates that miR-221 regulate E-cadherin expression in breast cancer cells through canonical interaction as previously reported22. Here, CDH1 is linked to breast cancer.