MPO and coronary artery disorder: NO2-Tyr (MPO-catalyzed nitration product) and Cl-Tyr (MPO-catalyzed chlorination product) contents are dramatically (6-fold higher than plasma) and selectively enriched within apoA-I recovered from atherosclerotic lesions in CHD patients [4, 8], oxidized apoA-I is in low abundance within the circulation, but accounts for 20% of the apoA-I in atherosclerotic plaque [9].