Moreover, HBV X protein is related to the cell cycle progression and hepatocarcinogenesis of HCC, and the mitochondrial protein SIRT4 has been demonstrated to upregulate the expression of p16 and p21 proteins, suppress cyclin B1/Cdc2 and Cdc25c, and suppress survivin to induce cell apoptosis [28]. Here, SIRT4 is linked to hepatocellular carcinoma.