Glycoantigen 724, or CA72-4 (gastric cancer antigen), is a laboratory marker for detecting gastric cancer and various GI cancers. Its presence or quantitative change can indicate the nature of tumors, and lend to the understanding of tumor histogenesis, cell differentiation, and cell function to help in tumor diagnosis, classification, prognosis judgment, and treatment guidance. A 3-fold higher glycoantigen 724 is mainly seen in gastric cancer, mucinous cystic adenocarcinoma of the ovary and non-small cell lung cancer. In addition, this index is also sensitive to tumors of the biliary system, colorectal cancer, pancreatic cancer, etc. Therefore, a 3-fold higher than normal value of glycoconjugate antigen 724 can also be considered to be caused by these cancers. However, CA72-4 is less specific and may not be clinically significant when elevated alone. It is generally recommended to perform abdominal CT and electronic gastroscopy if necessary. If malignant ulcers or other abnormal manifestations of the lining of the digestive tract are found, local biopsy, pathology and immunohistochemistry can be performed immediately to clarify the diagnosis. Once the diagnosis of gastric malignancy is confirmed, surgical resection is recommended for treatment.