There is a strong correlation between tau pathological burden in the brain and cognitive decline in AD [4–6], a finding bolstered by recent tau positron emission tomography imaging studies in AD [7, 8] and FTLD due to tau pathology [9, 10], suggesting that it is the development of abundant tau inclusions that ultimately leads to the neurodegeneration observed in AD and the other tauopathies. This evidence concerns the gene MAPT and Mental deterioration.