PCSK9 and coronary artery disorder: Genetics has provided strong support for the role of PCSK9 in atherosclerosis: loss-of-function mutations in PCSK9 are associated with lower levels of circulating LDL-C and a reduced risk of coronary heart disease [14–19]; whereas gain-of-function mutations, determining elevated LDL-C levels, cause familial hypercholesterolaemia (FH) and increase the risk of premature cardiovascular disease [20–24].