Furthermore, SIRT1 contributes to cellular tolerance in oxidative stress condition by activating Nuclear erythroid-related factor 2 (Nrf2) to promote the expression of antioxidant genes, such as glutathione S transferase [26], and regulates mitochondrial function through Peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α) [27], with both processes favouring, if altered, the development of DN. The gene discussed is SIRT1; the disease is liver dysplastic nodule.