The results showed an increase of H3k4ac and H3k9ac expression by 3 to 4-fold on BRCA1 and ESR2 genes promoters in both (ER+) cell lines, indicating that SIRT1 contributes to their repression through epigenetic chromatin modification; hence exerting oncogenic properties in breast cancer luminal subtypes. Here, BRCA1 is linked to breast cancer.