It has been suggested that the decrease in SIRT1 expression observed in the blood vessel walls of animals with streptozotocin diabetes may result from a decrease in NAD+ concentration in the cells; however, SIRT1 and AMPK expression is regulated in a different way in normoglycemic vascular smooth muscle cells following exposure to estradiol in vitro [43]. The gene discussed is SIRT1; the disease is diabetes mellitus.