Previous studies have shown that the overexpression or underexpression of PCSK9 has crucial effects not only on circulating PCSK9 and LDL-C levels but also on cardiovascular diseases such as familial hypercholesterolemia (FH), metabolic syndrome, and coronary atherosclerotic heart disease (CHD) [20]. This evidence concerns the gene PCSK9 and familial hypercholesterolemia.