F2 and liver disorder: HBV-related acute-on-chronic liver failure (HBV-ACLF) is an end-stage liver disease occurring on the basis of chronic HBV infection, with extensive hepatocellular necrosis, severe jaundice, and coagulopathy (prothrombin activity (PTA) <40% or international normalized ratio (INR) ≥1.5) in a short period of time, accompanied by serious complications such as ascites and/or hepatic encephalopathy and hepatorenal syndrome [4].