SIRT1 and neoplasm: Resveratrol, caloric restriction and oxidative stress induce autophagy and SIRT1 expression in tumor cell lines.29 In our study, autophagic cell death induced by sirtuin inhibition was enhanced in nutrient-deprived conditions, and the proliferation of SIRT1 and SIRT2 knockdown cells was only evident after 2 days in culture, a time point in which nutrient availability is limited in the culture media.