ESR1 and breast cancer: In another study genistein treatment of breast cancer cells in combination with cytotoxic agents, i.e., cisplatin, paclitaxel or tamoxifen, caused an increase in cell viability, and also in the antioxidant enzymes level, and decreased ROS production, autophagy, and apoptosis, plus enhanced the cell cycle S phase only in MCF-7 cells with a high ERα/ERβ ratio.