PCSK9 and familial hypercholesterolemia: The clinical benefit from discoveries concerning PCSK9 influence on lipid metabolism, was the implementation to the therapy of hypercholesterolemia, medications that inhibit function of PCSK9–monoclonal antibodies against circulating PCSK9 (PCSK9 mAbs: alirocumab and evolocumab) and inclisiran—a small interfering RNA (siRNA) which prevents from the translation of messenger RNA (mRNA) of PCSK9 and in that way decreases the production of mature protein in liver [12,13,14].