Flortaucipir shows excellent binding to the paired helical filament of tau deposited as NFTs in individuals with AD,10, 11, 12, 13, 14 matches well with the severity and regional distribution of NFTs staged by Braak in AD,15, 16, 17, 18, 19 and exceeds other diagnostic modalities in differentiating AD from other neurodegenerative diseases.20 This evidence concerns the gene MAPT and Alzheimer disease.