In comparison with liver tissue from patients who have HCC with or without cirrhosis, HBV or HCV can induce changes in specific genes in the process of DNA repair, cell cycle control, and signal transduction of apoptosis (RASSF1A, GSTP1, CHRNA3, and DOK1 are specific genes that exist in HCC tumors) [17, 18]. The gene discussed is DOK1; the disease is hepatocellular carcinoma.