Anti-pappalysin 1 antibodies are used for the immunodetection of the protein encoded by the PAPPA gene. In humans, the canonical protein has a reported length of 1627 amino acid residues and a mass of 181 kDa. It is known to be a secreted protein. It is notably expressed in the placenta and pregnancy serum. A member of the Peptidase M43B protein family, it is known to be involved with receptor-mediated signaling pathways and proteolysis. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include DIPLA1, IGFBP-4ase, PAPA, PAPPA1, IGF-dependent IGFBP-4 protease, and ASBABP2. Gene orthologs have been identified in the mouse, rat, bovine, frog, chimpanzee and chicken species. A number of pappalysin 1 antibodies have been mentioned in research publications and have associated citations. ELISA is a widely used application for these antibodies. Western Blot and Immunohistochemistry are also common applications.