Anti-OPRPN antibodies are used in the immunodetection of the protein opiorphin prepropeptide. In humans, the canonical protein has a reported length of 248 amino acid residues and a mass of 27.2 kDa. It has been described to be a secreted protein. It is found to be highly expressed in lacrimal gland where it found in the secretory endpieces. It is a member of the PROL1/PROL3 protein family. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include basic proline-rich protein, proline rich, lacrimal 1, proline-rich 1, proline-rich protein 1, and basic proline-rich lacrimal protein. OPRPN gene orthologs have been reported in the rat and chimpanzee species. Some OPRPN antibodies may have been used in research and have associated citations. Immunocytochemistry is a widely used application for these antibodies. ELISA, Western Blot, Immunofluorescence, and Immunohistochemistry are also common applications.