MAPT and Alzheimer disease: Aoyagi et al.’s (2019) study quantically measures the intracellular self-propagating conformers in postmortem brain samples from AD patients and shows that the longevity-dependent reduction in self-propagating tau conformers were identified in spite of increasing levels of total insoluble tau, demonstrating an inverse correlation between longevity and the amounts of pathological tau conformers in AD patients.