Jo et al. [164] discovered that PD0332991, a highly selective inhibitor of CDK4/CDK6 kinases with the ability to block phosphorylation activity of retinoblastoma (Rb) [186], can significantly enhance the expression of SIRT3 in hepatocellular carcinoma cells, thus improving the anti-cancer action of sorafenib [164], also known as Nexavar, an orally active multikinase inhibitor, which has been used as a first-line chemotherapeutic agent [187]. This evidence concerns the gene SIRT3 and hepatocellular carcinoma.