Anti-MUC13 antibodies are used in the immunodetection of the protein mucin 13, cell surface associated. In humans, the canonical protein has a reported length of 512 amino acid residues and a mass of 54.6 kDa. Its subcellular localization is in the cell membrane and is secreted. It is notably expressed in the small intestine, rectum, duodenum, colon, and appendix. Post-translational modifications have been described, including N-glycosylation and protein cleavage. Synonyms for this target antigen include down-regulated in colon cancer 1, mucin 13, epithelial transmembrane, and mucin-13. MUC13 gene orthologs have been reported in the mouse, rat, bovine, frog, chimpanzee and chicken species.