ApoB

Apolipoprotein B (ApoB) is the structural protein of atherogenic lipoproteins, including LDL, VLDL, IDL, and Lp(a). Because ApoB-100 is typically present as approximately one molecule per atherogenic particle, plasma ApoB serves as a clinical proxy for atherogenic particle number. Multivariable Mendelian randomization (e.g., Richardson et al.) prioritizes ApoB and particle burden as the causal lipid driver of coronary artery disease, making ApoB a more accurate predictor of cardiovascular events and mortality than LDL cholesterol alone. Lower ApoB is associated with reduced atherosclerotic disease.