APOB and coronary artery disorder: ApoB-containing particles exist on a spectrum of varying sizes, densities, and particle compositions, and identification of specific subfractions that contribute to different forms of ASCVD may have implications for pathophysiology, molecular mechanisms, risk stratification, and treatment.37 Variability in the distribution of ApoB within lipoprotein subfractions may contribute to differential risk of PAD compared with CAD.