MPO and coronary artery disorder: It is possible that the detection of circulating MPO underestimates the actual amount of MPO sequestered within the vessel wall, as MPO has been shown to rapidly bind to heparan-sulfated glycosaminoglycans (GAGs) and deposit within the sub endothelium of the vessel wall, suggesting increased sequestration of leukocyte-derived MPO in CAD patients [25, 26].