Anti-PGAP4 antibodies are used in the immunodetection of the protein post-GPI attachment to proteins GalNAc transferase 4. In humans, the canonical protein has a reported length of 403 amino acid residues and a mass of 46.6 kDa. Its subcellular localization is in the Golgi. It is a member of the PGAP4 protein family. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include transmembrane protein 246, transmembrane protein C9orf125, and post-GPI attachment to proteins factor 4. PGAP4 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.