Four cell cycle-related genes (CDK4, CHEK1, CCNB1, and CDKN2A) were used to establish a risk score to predict the overall survival (OS) of patients with hepatocellular carcinoma (LIHC) in TCGA training set using LASSO Cox regression analysis (Figure 8D and 8E). The gene discussed is CHEK1; the disease is hepatocellular carcinoma.