There is a clear accumulation of APOE-4 carriers among patients with AD (APOE-3/4 30.30%; APOE-4/4 6.06%) (P < 0.001) and vascular dementia (APOE-3/4 35.85%, APOE-4/4 6.57%) (P < 0.001) as compared to controls. The gene discussed is APOE; the disease is Alzheimer disease.