ESR1 and breast cancer: In previous studies, we have demonstrated that the distinct ER status of breast cancer cells is correlated to different microRNA (miRNA) epigenetic signatures and that specific miRNAs (i.e., miR-10b, miR-145 and miR-200b) are possible biomarkers for regulating breast cancer cell behavior by interacting with matrix mediators (19, 20, 53, 54).