The expression of Bcl-2, an anti-apoptotic or pro-survival protein, was markedly decreased in MCF-7 and MDA-MB-231 breast cancer cells following the inhibition of SIRT1 with sirtinol [51], which indicates that SIRT1 promotes the growth of breast cancer through the upregulation of the Bcl-2 protein. This evidence concerns the gene SIRT1 and breast cancer.