The Apoe or Ldlr deficient rats showed some phenotypic variations in atherosclerosis according to type of deficient genes and the way to induce atherosclerosis (eq. high-fat diet (HFD) duration, artificial induction of endothelial injury, etc.), but the previous reports have been focused on phenotyping typical atherosclerosis at later stage which is classically represented by plaque formation in mice. The gene discussed is APOE; the disease is atherosclerosis.