Although this study did not investigate the role of SAE1 in the cell proliferation of HCC, its in vitro experiments exhibited that the downregulation of SAE1 in HCC cells resulted in decreased protein levels of some cell cycle-related genes such as CDK4 and cyclin B1 [45], supporting the findings of this study that SAE1 regulated cell cycle and proliferation of HCC. The gene discussed is CDK4; the disease is hepatocellular carcinoma.