GALNT13 (Polypeptide N-Acetylgalactosaminyltransferase 13) is a gene that encodes an enzyme involved in initiating O-linked glycosylation, a crucial post-translational modification process. It transfers N-acetylgalactosamine (GalNAc) to specific protein sites within the Golgi apparatus, influencing protein trafficking, secretion, and cell surface interactions. GALNT13 contributes to cell signaling, adhesion, and immune response, with its dysregulation associated with diseases such as cancer and metabolic disorders.