ApoE is a ligand for both LDL receptor and LRP and plays an important role in the catabolism of remnant lipoproteins in the liver and genetic deficiency of apoE is a cause of human type III hyperlipoproteinemia (Mahley, 1988; Mahley et al., 1999). The gene discussed is APOE; the disease is hyperinsulinemic hypoglycemia, familial, 4.