Glycoantigen CA724 is a non-specific tumor marker for gastrointestinal tumors, which is mainly indicative for gastrointestinal tumors, biliary tract tumors, non-small cell lung cancer and gynecological malignancies such as ovarian cancer. However, clinically, an elevated level of glycoantigen 724 does not mean malignant tumor, but needs to be further clarified with the results of other tests. Therefore, no matter how high the value of glycogen antigen is, it is not completely certain that cancer is present. However, it is clinically important to take note of a level higher than 2 times the upper limit of the test, and also to do dynamic and continuous tests to clarify the possibility of the presence of cancer. In general, the normal value of glycoantigen 724 is 0-6.9 U/ml. If there is a mild elevation of this indicator, it should be considered to be caused by chronic gastritis or chronic pancreatitis and adnexitis in women. If the test results indicate an exponential increase in this index, combined with elevated CA125 or CEA or CA199, it should be taken seriously and gastroscopy, colonoscopy and lung CT should be done as soon as possible to exclude gastric cancer, intestinal cancer and lung cancer. Once the diagnosis of gastrointestinal malignant tumor and lung cancer is confirmed, it is recommended to have surgery to remove the tumor according to the specific condition in time.