CYBB and chronic kidney disease: Importantly, the expression levels of NOX2 and its regulatory subunits p47phox, p22phox and p67phox are increased in high calcium-induced CKD rats, human aortic smooth muscle cells, and rabbit calcified aortic valves, indicating that NOX2 may provide a potential therapeutic target in alleviating vascular and valvular calcification [99,105,106].