The authors also suggested that, in hippocampal sparing AD, tau pathology may begin in the neocortex, since they found a fourfold increase in the amount of neocortical late-stage tau (antibody Ab39 to a conformational epitope in NFTs detecting late-stage tangles [25]) in hippocampal sparing AD compared with typical AD [24]. This evidence concerns the gene MAPT and Alzheimer disease.