As shown in Fig. 6A, C, E, and G, the mRNA expression levels of CCNB1 (P = 2.66e-28), CDK4 (P = 2.494e-18), CDK1 (P = 6.273e-28), and PLK1 (P = 1.584e-27) in the HCC group were significantly higher than those in the normal group. This evidence concerns the gene CDK4 and hepatocellular carcinoma.