By performing univariate Cox analysis of the TCGA (the training set) and GEO (GSE14520) datasets, we ultimately identified 11 DEAGs (GHR, FOXM1, PON1, TOP2A, FEN1, HELLS, BUB1B, PPARGC1A, PRKDC, and H2AFX) correlated with the prognosis of patients with HCC (P < 0.05) for subsequent determination of the molecular subtypes of HCC (Supplementary Table 1). The gene discussed is FEN1; the disease is hepatocellular carcinoma.