MPO and blood coagulation disease: Furthermore, experiment has shown that the MPO level was significantly raised in patients with coagulation disorders [61], and also the elevated MPO as an oxidase affects the endothelial function, phenotype and viability, ultimately leading to ED: (1) production through oxidants (HOCI, HOSCN, and NO2), (2) catalytic consumption of NO and (3) non-catalytic biological activity of recently discovered enzymes [59].