XDH and metabolic disease: In the pathogenesis of metabolic disorders, for instance, hypertriglyceridemia and nonalcoholic fatty liver disease, hepatic fatty acid oxidation may induce hypoxia-inducible factor-1α (HIF-1α), which in turn transcriptionally activates xanthine dehydrogenase (XDH) and cytoplasmic-5 ́-nucleotidase-II (NT5C2) in the uric acid synthesis pathway and promotes hepatic uric acid synthesis (43, 44).