SIRT1 and neoplasm: Tip60-mediated p53 acetylation at K120, collaborating with PIASy-mediated K386 sumoylation, functions as a death signal to promote p53 cellular accumulation and autophagy.114 In addition, TFAM knockdown in tumor cells increases NAD(+)/NADH ratio and leads to SIRT1 upregulation to deacetylate p53 at K382 sites, which disturbs autophagy via weakening transcriptional regulation of the PISD enhancer.115 IKKα plays a cytoprotective role when treating human hepatoma cells with the antitumor therapeutic reagent arsenite.