Hypercholesterolemia is a heterogeneous condition encompassing two main disorders, namely familial hypercholesterolemia (FH) carrying LDL, LDLR, APOB, PCSK9- and LDLRAP1-related genetic defects, and polygenic hypercholesterolemia (PH) due to multiple genetic variants. This evidence concerns the gene PCSK9 and familial hypercholesterolemia.