Proprotein convertase subtilisin/kexin 9 (PCSK9) is the ninth member of the 
proprotein convertase family. It is an important regulator of cholesterol 
metabolism. PCSK9 can bind to low-density lipoprotein receptors (LDLRs) and 
induce the degradation of these receptors through the endosome/lysosome pathway, 
thus decreasing the LDLR levels on the cell surface of hepatocytes, resulting in 
increased serum low-density lipoprotein cholesterol (LDL-C) concentrations. 
Recent studies have found that gene polymorphisms of PCSK9 are associated with 
hypercholesterolemia, risk of atherosclerosis, and ischemic stroke. Furthermore, 
monoclonal antibodies, peptide mimetics, small molecule inhibitors and gene 
silencing agents that are associated with PCSK9 are some of the newer 
pharmaceutical therapeutic strategies and approaches for lowering serum LDL-C 
levels. In this review, we will discuss recent advances in PCSK9 research, which 
show that PCSK9 is correlated with lipid metabolism, atherosclerosis, and, in 
particular, ischemic stroke. We will also discuss the current state of PCSK9 
therapeutics and their potential in modulating these diseases.