Anti-hemopexin antibodies are used for the immunodetection of the protein encoded by the HPX gene. In humans, the canonical protein has a reported length of 462 amino acid residues and a mass of 51.7 kDa. It is known to be a secreted protein. It is notably expressed by the liver and secreted in plasma. A member of the Hemopexin protein family, it is known to bind heme and transports it to the liver for breakdown and iron recovery, after which the free hemopexin returns to the circulation. Post-translational modifications have been described, including O-glycosylation. Other names for this target antigen include beta-1B-glycoprotein, epididymis secretory sperm binding protein, and HX. Gene orthologs have been identified in the mouse, rat, bovine, frog, chimpanzee and chicken species.