LDLR and familial hypercholesterolemia: In 2013, al-Mashhadi et al. generated proprotein convertase subtilisin/kexin type 9 (PCSK 9) mutation pigs, which exhibited reduced low-density lipoprotein receptor (LDLR) levels and developed severe hypercholesterolemia and spontaneous atherosclerosis (Renner et al., 2010).