In agreement with these observations, patients clinically diagnosed with dementia of AD type and mild cognitive impairment (MCI) exhibit significantly higher in vivo [F-18]-AV-1451 retention than cognitively normal individuals in regions that are known to contain an elevated burden of tau lesions in AD [4, 6, 7, 11, 16, 25, 28, 33]. This evidence concerns the gene MAPT and Alzheimer disease.