Mucin-17 (MUC17) is a membrane-tethered mucin and a member of the mucin family. Mucin family members play crucial roles in protecting epithelial cells, providing lubrication, maintaining epithelial integrity, aiding in cell adhesion, and offering protection against pathogens, toxins, and foreign particles. MUC17's expression changes have been observed in various pathological conditions, especially in cancer and inflammatory bowel diseases. The biosynthesis of MUC17 occurs in the endoplasmic reticulum of goblet cells and may undergo N-glycosylation either before or after dimerization. In tumor tissues, the abnormal expression of MUC17 is correlated with tumor invasion, metastasis, and prognosis. In recent years, MUC17 has been recognized as an important biomarker for certain cancers and a promising therapeutic target. Particularly, the role of MUC17 in gastric cancer (GC) has attracted researchers' attention. According to one study, MUC17 is highly expressed in gastric cancer tissues and is associated with a favorable prognosis for patients.