Anti-HM13 antibodies are used in the immunodetection of the protein histocompatibility minor 13. In humans, the canonical protein has a reported length of 377 amino acid residues and a mass of 41.5 kDa. Its subcellular localization is in the ER and cell membrane. Up to 4 different isoforms have been reported for this protein. It is reported to be widely expressed with highest levels in the kidney, liver, placenta, lung, leukocytes and small intestine and reduced expression in the heart and skeletal muscle. A member of the Peptidase A22B protein family, HM13 is known to catalyze intramembrane proteolysis of some signal peptides after they have been cleaved from a preprotein, resulting in the release of the fragment from the ER membrane into the cytoplasm. Synonyms for this target antigen include intramembrane protease 1, minor histocompatibility antigen 13, presenilin-like protein 3, signal peptide peptidase beta, signal peptide peptidase like 1, and minor histocompatibility antigen H13. A number of HM13 antibodies have been mentioned in research publications and have associated citations. Western Blot is a widely used application for these antibodies. ELISA and Immunofluorescence are also common applications.