Anti-MUC21 antibodies are used in the immunodetection of the protein mucin 21, cell surface associated. In humans, the canonical protein has a reported length of 566 amino acid residues and a mass of 54.2 kDa. Its subcellular localization is in the cell membrane. Up to 3 different isoforms have been reported for this protein. It is reported to be expressed in the lung, large intestine, thymus, and testis. Post-translational modifications have been described, including O-glycosylation. Synonyms for this target antigen include mucin-21 and epiglycanin. MUC21 gene orthologs have been reported in the mouse, bovine and chimpanzee species. Some MUC21 antibodies may have been used in research and have associated citations. Immunohistochemistry is a widely used application for these antibodies. Immunocytochemistry and Immunofluorescence are also common applications.