With the use of one-dimensional sodium dodecyl sulfate–polyacrylamide gel electrophoresis (1D SDS-PAGE), in-gel digestion, nano-liquid chromatography tandem mass spectroscopy (LC-MS/MS), PEAKS 7 software, and immunoprecipitation–Western blotting (IP-WB) to analyze pooled plasma samples (healthy controls (HCs) versus CAD patients with various levels of stenosis (≤50% and >50%), we identified and validated novel HNE modifications that were detected to have a molecular weight close to 25 kDa and denoted as ApoA-I (Figure 2, Table 2). Here, APOA1 is linked to coronary artery disorder.