AFP and hepatocellular carcinoma: Both American Association for the Study of Liver Disease (AASLD) and European Association for the Study of the Liver (EASL) suggest that it is necessary to monitor HCC in high-risk patients partly by abdominal ultrasonography every six months, but there exists argument in the use of AFP as an auxiliary monitoring test and there is no identified threshold of AFP when the combination of AFP and ultrasound is used to monitor HCC [25, 26].