This gene encodes GalNAc transferase 7, a member of the GalNAc-transferase family.The enzyme encoded by this gene controls the initiation step of mucin-type O-linked protein glycosylation and transfer of N-acetylgalactosamine to serine and threonine amino acid residues.This enzyme is a type II transmembrane protein and shares common sequence motifs with other family members.Unlike other family members, this enzyme shows exclusivefor partially GalNAc-glycosylated acceptor substrates and shows no activity with non-glycosylated peptides.This protein may function as a follow-up enzyme in the initiation step of O-glycosylation.[provided by RefSeq]