E2F1 and breast cancer: Zhao and colleagues (45) performed a study indicating that the levels of miR-372, a regulator of E2F1, were significantly decreased in tissue samples from patients with primary breast cancer, including both tumor and adjacent non-tumor tissues, as well as in several breast cancer cell lines (BT-474, MCF-7, MDA-MB-436, and MDA-MB-231), compared to normal breast tissue cell lines.