SIRT1 and hepatocellular carcinoma: Considering our previous findings of an increased radiosensitivity in SirT1-deficient hepatoma cells under both normoxia and hypoxia45, a reasonable clinical treatment strategy can be suggested to improve the efficiency of radiotherapy by intervening SirT1 gene expression in hepatocellular carcinoma to enhance its radiosensitivity as well as moderating the activation of ER stress in hepatocytes to protect normal cells.