LDLR and atherosclerosis: So far, there has been only a small number of papers suggesting Apoe or Ldlr knockout rat as an atherosclerosis model which were generated with engineered endonucleases: TALEN-mediated Apoe knockout26, ZFN-mediated Ldlr knockout27, and CRISPR/Cas9-mediated knockout of Apoe or Ldlr28 in rats.