There is an increasing body of evidence that abnormal expression of genes and mutations of tumor-suppressor genes are associated with mechanisms of HCC tumorigenesis and progression, including cyclin D1 (CCND1), pre-mRNA processing factor 3 (PRPF3), c-Myc or Ras and p53 (Choi et al., 2001; Wang et al., 2012; Li et al., 2017a; Liu et al., 2020). The gene discussed is CCND1; the disease is hepatocellular carcinoma.