Proprotein convertase subtilisin/kexin type 9 (PCSK9) is now identified as an important and major player in the pathophysiology of atherosclerosis.202 PCSK9 is a soluble protein synthesized as a zymogen, and degrades LDL receptors (LDLR) upon activation by autocatalytic cleavage in the ER and subsequently increases LDL cholesterol (LDL-C) levels. This evidence concerns the gene LDLR and atherosclerosis.