Accordingly, different therapeutic approaches have been considered for attenuating serum cholesterol and therefore for preventing the development and progression of AD such as using inhibitors of HMG-CoA reductase (17) and Acyl-coenzyme A: cholesterol acyl-transferase (ACAT) (18) or dietary supplementation of vitamin E or vitamin C (19). This evidence concerns the gene HMGCR and Alzheimer disease.