SIRT1 and cancer: SIRT-1 is NAD+ dependent and is involved in many cellular processes from DNA repair, cell cycle and metabolism to cancer process, aging and cell survival under stress conditions through deacetylation of histone and non-histone substrates.41,44 In addition, SIRT-1 has been found to play an important role in rare genetic mutations, pathogenesis of solid tumors and leukemias as well as drug resistance.