BRCA1 and breast cancer: Furthermore, we showed that SIRT1 depletion increases histone H3 acetylation levels in a subtype-specific manner at 6 breast cancer-related gene promoters: AR, BRCA1, ERS1, ERS2, EZH2, and EP300, suggesting that SIRT1 could play an active role in regulating their expression in breast cancer pathogenesis.