Anti-KLK9 antibodies are used in the immunodetection of the protein kallikrein related peptidase 9. In humans, the canonical protein has a reported length of 250 amino acid residues and a mass of 27.5 kDa. It has been described to be a secreted protein. Up to 2 different isoforms have been reported for this protein. It is notably expressed in the vagina, skin, oral mucosa, esophagus, and cervix. A member of the Peptidase S1 protein family, KLK9 is known to be involved with proteolysis. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include kallikrein-9 and kallikrein-like protein 3. KLK9 gene orthologs have been reported in the mouse, rat, bovine and chimpanzee species. Some KLK9 antibodies may have been used in research and have associated citations. ELISA, Western Blot, and Immunohistochemistry are common applications for these antibodies.