Elevated gamma-glutamyl transpeptidase is indicative of problems, such as viral hepatitis, cirrhosis, pancreatitis, cholangitis, and other diseases; such as exertion, staying up late, drinking alcohol, and taking medication, etc. Low gamma-glutamyl transpeptidase may also be problematic, such as chronic cirrhosis and liver cancer. Normal values of γ-glutamyl transpeptidase are 11-50 U/L for men and 7-32 U/L for women. 1. Mildly or moderately elevated: can be seen in cases of exertion, staying up late, drinking alcohol, taking medication, viral hepatitis, pancreatitis, alcoholic liver disease and so on. 2. Significantly elevated: seen in primary or secondary hepatocellular carcinoma, hepatic obstructive jaundice, biliary cirrhosis, cholangitis, pancreatic head carcinoma, extrahepatic biliary tract carcinoma and so on. 3. Low: In chronic liver diseases, especially chronic cirrhosis, the value can be persistently low. For the interpretation of γ-glutamyl transpeptidase, it is recommended to consult a doctor for judgment in the light of the specific value and personal condition.