GGT refers to gamma-glutamyl transpeptidase, which is widely distributed in human tissues, most in the kidney, followed by the pancreas and liver. The normal value of GGT is 0-40U/L. High GGT can be caused by hepatitis, cirrhosis, fatty liver, hepatocellular carcinoma, pancreatic cancer, bile duct cancer and so on. Elevated GGT needs ultrasound and CT examination of liver, gallbladder, pancreas and spleen to exclude malignant tumor and then treat it actively.