For transthyretin, glutamyl transpeptidase is widely found in human tissues such as kidney, pancreas and liver. For liver, it is mainly found in hepatocytes and epithelial cells of bile ducts, and its normal value is between 3 and 50 U/L. The transpeptidase in the liver function test is mostly considered to come from the liver, for this case, if it is mildly elevated, the patient should be considered to continue to observe, and blood should be drawn after a month to check the liver function of the patient to see how much transpeptidase is. If the transpeptidase is further elevated, we should consider whether the patient has the possibility of hepatitis, especially viral hepatitis, and whether the patient has the possibility of cirrhosis and liver fibrosis. In some patients with obstructive jaundice and hepatocellular carcinoma, elevated glutamyl transferase may also occur. For some patients who have been drinking alcohol or taking medications for a long time, patients may also have elevated transaminases. Patients with elevated transaminases, elevated alkaline phosphatase, elevated total bilirubin and elevated direct bilirubin are most likely to have biliary obstruction. If necessary, the patient should have an enhanced CT or MRI of the upper abdomen to determine whether there are other lesions in the biliary tract or liver.