Due to economic considerations of some patients or the medical examination population, as well as the lack of awareness of some medical personnel, it is often the case that biochemical labs do not include GGT (glutamyl transpeptidase). This indicator is often neglected in clinical practice, thus causing undesirable consequences. 1.When intrahepatic or extrahepatic bile duct obstruction, due to the obstruction of glutamyl transpeptidase excretion, with bile back into the blood, there will also be high glutamyl transpeptidase. 2.Alcoholic hepatitis and alcoholic cirrhosis as well as drug-related liver damage patients almost all have elevated glutamyl transpeptidase, which becomes an important feature of alcoholic liver disease and drug-related liver damage. 3.In patients with primary or metastatic liver cancer, most of glutamyl transpeptidase is moderately or highly increased, which can be several times or even tens of times greater than normal. 4.Early stage of primary or secondary biliary cirrhosis, elevated glutamyl transpeptidase may also appear. 5, fatty liver patients will also appear elevated glutamyl transpeptidase, but generally in nutritional fatty liver, serum glutamyl transpeptidase activity mostly does not exceed two times the normal value.