From the clinical parameters of patients provided by the hospital, it was observed that the vast majority of liver cancer patients also suffer from hepatitis B. In this study, the IL‐18 concentration (1048.88; 730.04–1185.10 pg/mL) in the serum of patients with liver cancer was higher than that of healthy controls and patients with four other liver diseases, indicating that the IL‐18 concentration can reflect liver damage severity to a certain extent. Here, IL18 is linked to hepatitis B virus infection.