PCSK9 inhibitors like evolocumab and alirocumab are FDA-approved drugs for treating adult heterozygous familial hypercholesterolemia (FH) and clinical atherosclerotic cardiovascular diseases via inhibiting the binding of circulating PCSK9 and LDLR, enhancing the clearance of LDL-c from circulation. Here, PCSK9 is linked to familial hypercholesterolemia.