Aberrant expression of histone-modifying enzymes, including lysine-specific demethylase 1 (LSD1), histone deacetylase 2 (HDAC2) and silent mating-type information regulation 2 homologue 1 (SIRT1), has been shown to have a role in breast cancer development[4–9] as well as prognostic value for breast cancer[10]. The gene discussed is SIRT1; the disease is breast carcinoma.