PCSK9 and familial hypercholesterolemia: The relevance of PCSK9 in atherosclerosis and related CVD has been established by the observation that subjects carrying loss-of-function mutation in PCSK9 gene exhibit lower LDL-C levels and a substantial reduction in cardiovascular risk [3], while gain-of-function variants are associated with familial hypercholesterolemia and, as a consequence of the lifelong exposure to elevated levels of LDL-C, increased CV risk [4].