For instance, Zhang et al [28] in a case-control study in a tertiary care referral center, compared 158 patients with documented CAD against 175 patients without angiographically significant CAD (controls) and found that both leukocyte- and blood-MPO levels were significantly greater in patients with CAD with an odds ratio (OR) of 20.4 (95% CI, 8.9-47.2) for the highest vs. lowest quartiles of plasma MPO levels. The gene discussed is MPO; the disease is coronary artery disorder.