Cryo-EM studies of tau fibrils obtained from brain of human patients with distinct tauopathies [AD, PiD and chronic traumatic encephalopathy (CTE)] have revealed that each tauopathy has characteristic filament folds, which are conserved among individuals with the same disease, yet different from structures obtained from in vitro aggregation of recombinant tau (148–150). The gene discussed is MAPT; the disease is Alzheimer disease.