Anti-BPI antibodies are used in the immunodetection of the protein bactericidal permeability increasing protein. In humans, the canonical protein has a reported length of 487 amino acid residues and a mass of 53.9 kDa. Its subcellular localization is in the cytoplasm and is secreted. It is notably expressed in the bone marrow. A member of the BPI/LBP protein family, BPI is known to be involved with the cellular response to lipopolysaccharides and innate immune responses. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include rBPI, BPI fold containing family D, member 1, CAP 57, recombinant BPI holoprotein, rBPI, and BPIFD1. BPI gene orthologs have been reported in the mouse, rat, bovine, frog, chimpanzee and chicken species. A number of BPI antibodies have been mentioned in research publications and have associated citations. Western Blot is a widely used application for these antibodies. ELISA, Immunofluorescence, and Immunohistochemistry are also common applications.