Compared to that of the lowest ADA level group (Q1), the OR values for the risk of developing HCC in the Q2, Q3, and Q4 groups were 2.049 (1.279–3.280), 1.998 (1.231–3.244), and 2.203 (1.362–3.563), respectively, and the adjusted OR values were 1.974 (0.902–4.322), 1.272 (0.566–2.86), and 1.635 (0.705–3.789), respectively. The gene discussed is ADA; the disease is hepatocellular carcinoma.