Elevated levels of XDH/XO in the serum were found in pathological situations, such as rheumatic and autoimmune diseases, schizophrenia, type 2 diabetes, hypertension, dyslipidemia and cancer, and it was proposed that proinflammatory and prothrombotic activities of endothelial cells induced by high levels of circulating XDH/XO may contribute to the pathogenesis of atherosclerosis [53]. Here, XDH is linked to type 2 diabetes mellitus.