The results show that the expressions of two up-regulated hub genes (TTK, BUB1) and three down-regulated hub genes (CYP3A4, NR1I2, CYP8B1) in tumor and normal samples were consistent with their differential expression analysis: TTK and BUB1 were overexpressed, while CYP3A4, NR1I2, and CYP8B1 were low in expression in HCC respectively (Figures 7E–I). The gene discussed is CYP3A4; the disease is hepatocellular carcinoma.