GALNT3 (Polypeptide N-Acetylgalactosaminyltransferase 3): GALNT3 is involved in the process of O-linked glycosylation, where it adds N-acetylgalactosamine to proteins. This modification is important for protein function and cell signaling. Mutations in GALNT3 can lead to disorders such as familial tumoral calcinosis, characterized by abnormal calcium phosphate deposits in the body....