ESR1 and breast cancer: Genistein is involved in regulation of key biological processes including those in different types of cancer via epigenetic modulation in a direct or indirect manner through estrogen-receptor-dependent pathways, where it was reported to target estrogen receptor (ER), human epidermal growth factor receptor-2 (HER2), and breast cancer gene-1 (BRCA-1) in multiple BC cell lines [279,280].