APOE and hyperinsulinemic hypoglycemia, familial, 4: While apoE deficiency is rare in humans, the importance of apoE in plasma lipoprotein homeostasis was confirmed in subjects with type III familial hyperlipoproteinemia (dysbetalipoproteinemia), where the elevated plasma triglyceride and cholesterol levels and increased atherosclerosis risk were attributed to the ε2 allele in the APOE gene [35].