Glycoconjugate antigen 724, also known as CA724, is a gastric cancer-related antigen. The clinical significance of CA724 detection is mainly as follows: 1. It has a high specificity for gastric cancer diagnosis. C724 detection, when combined with glycoconjugate antigen 199 and carcinoembryonic antigen, can monitor more than 70% of gastric cancers. 2. It has obvious correlation with the stage of gastric cancer. That is, the higher the concentration of CA724 in the blood, the more advanced the stage of gastric cancer. 3. Monitoring postoperative recurrence. After surgical resection and treatment, CA724 concentration in the blood of gastric cancer patients will drop rapidly to normal level, and will rise significantly again when recurrence occurs.