Anti-Xanthine Dehydrogenase antibodies are used in the immunodetection of the protein encoded by the XDH gene. In humans, the canonical protein has a reported length of 1333 amino acid residues and a mass of 146.4 kDa. Its subcellular localization is in the cytoplasm and is also secreted. It is notably expressed in milk. A member of the Xanthine dehydrogenase protein family, it is known to be a key enzyme in purine degradation. Post-translational modifications have been described, including protein cleavage. Other names for this target antigen include XO, XOR, xanthine dehydrogenase/oxidase, xanthine oxidoreductase, and XAN1.