Anti-KEL antibodies are used in the immunodetection of the protein Kell metallo-endopeptidase (Kell blood group). In humans, the canonical protein has a reported length of 732 amino acid residues and a mass of 82.8 kDa. Its subcellular localization is in the cell membrane. It is notably expressed at high levels in erythrocytes and testis (in Sertoli cells), and, at lower levels, in skeletal muscle, tonsils (in follicular dendritic cells), lymph node, spleen and appendix. A member of the Peptidase M13 protein family, KEL is known to be involved with cellular localization and the regulation of intracellular calcium. Synonyms for this target antigen include ECE3, Kell, kell blood group glycoprotein, Kell blood group, metallo-endopeptidase, Kell glycoprotein, and CD238. KEL gene orthologs have been reported in the mouse, rat, bovine, chimpanzee and chicken species. A number of KEL antibodies have been mentioned in research publications and have associated citations. Western Blot is a widely used application for these antibodies. In addition, ELISA is also a common application.