Kaplan–Meier survival analysis of data from GEPIA revealed that HCC patients with high expression (n = 182) of AGXT2 (HR = 0.66, P = 0.019), DAO (HR = 0.61, P = 0.005), and CTH (HR = 0.67, P = 0.024) had a better prognosis than patients with low expression (n = 182) of AGXT2, DAO, and CTH, while HCC patients with low BPGM (HR = 1.6, P = 0.010), CBS (HR = 1.4, P = 0.049), PSPH (HR = 1.4, P = 0.045), and ACOT7 (HR = 2, P < 0.001) were associated with a longer OS rate (Figure 5). The gene discussed is DAO; the disease is hepatocellular carcinoma.