To sum up, treatment with IL‐33 attenuated hepatic steatosis induced by diet but aggravated hepatic fibrosis through an ST2‐dependent manner.16 In patients with hepatitis B virus infection or hepatitis C virus infection, plasma IL‐33 levels were significantly increased, and the concentration changes were consistent with serum ALT levels.17, 18 The protective role of the IL‐33‐ST2 axis in concanavalin A‐induced severe hepatitis has received attention. Here, IL33 is linked to hepatitis A virus infection.