The discovery of proprotein convertase subtilisin kexin type 9 (PCSK9) and the subsequent observations that genetic mutations in PCSK9 can drastically affect low density lipoprotein cholesterol (LDL-C) levels and the risk for cardiovascular disease ushered in a new era of understanding about the regulation of circulating LDL-C [1-6]. The gene discussed is PCSK9; the disease is cardiovascular disorder.