PCSK9 and Hypercholesterolemia: The role of PCSK9 as a regulator of LDLRs and in development of hypercholesterolemia is well described (Grefhorst et al. 2008; Lambert et al. 2008; Seidah 2013) and overexpression of PCSK9 accumulates LDL in the circulation (Benjannet et al. 2004; Lalanne et al. 2005; Lambert et al. 2006).