Anti-CTSE antibodies are used in the immunodetection of the protein cathepsin E. In humans, the canonical protein has a reported length of 396 amino acid residues and a mass of 42.8 kDa. Its subcellular localization is in the endosome. Up to 3 different isoforms have been reported for this protein. It is noted to be expressed abundantly in the stomach, the Clara cells of the lung and activated B-lymphocytes, and at lower levels in lymph nodes, skin and spleen. A member of the Peptidase A1 protein family, CTSE is suspected to have a role in immune function. Synonyms for this target antigen include erythrocyte membrane aspartic proteinase, slow-moving proteinase, and CATE. CTSE gene orthologs have been reported in the mouse, rat, frog, chimpanzee and chicken species. A number of CTSE 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.