ESR1 and breast cancer: To know if MED1 mediated induction of miR-191/425 is ER-dependent, we overexpressed MED1 in both ER+ve (MCF7, ZR-75) and ER-ve (MDA-MB-231) breast cancer cell lines and found that MED1 mediated induction of miR-191/425 is limited to ER+ve background (Fig. 3D).