Treatment of MCF7 and MDA-MB-231 breast cancer cells with genistein (18.5 μmol/L) and daidzein (78.5 μmol/L) decreased histone trimethylation and increased histone acetylation of six different genes each responsible for a protein associated with breast cancer (histone-lysine N-methyltransferase (EZH2), breast cancer 1, early onset (BRCA1), oestrogen receptor α (ERα), oestrogen receptor β (ERβ), nuclear receptor coactivator 3 (SRC-3), and P300) [137]. The gene discussed is BRCA1; the disease is breast cancer.