N-Acetylgalactosaminyltransferase 1 (GALNT1) is a glycosyltransferase that initiates mucin-type O-glycosylation by transferring α-GalNAc from UDP-GalNAc to serine (Ser) or threonine (Thr) residues in proteins. Overexpression of N-Acetylgalactosaminyltransferase 1 in gastric cancer promotes the Wnt/β-catenin signaling pathway through abnormal O-glycosylation of CD44, thereby enhancing malignancy. N-Acetylgalactosaminyltransferase 1 plays a crucial role in cancer growth and metastasis by modifying O-glycosylation of various glycoproteins, such as mucin (MUC1), osteopontin (OPN), matrix metalloproteinase-14 (MMP14), and integrin α3^[1].