APOE and Alzheimer disease: When we excluded APOE variants, the contribution of the pathways to the total polygenic risk of AD was 45.5% for immune response, 19.2% for endocytosis, 13.7% for ß-amyloid metabolism, 8% for cholesterol/lipid dysfunction, 1.4% for angiogenesis and 12.3% for the unmapped variants (Fig. 4b).