MAPT and Alzheimer disease: Inoculation of AD sarkosyl-insoluble fractions produced 3Rtau and 4Rtau neuronal deposits at 3 months and 6 months after inoculation, only 4Rtau deposits following inoculation of progressive supranuclear palsy (PSP) and CBD-tau-enriched fractions, and only 3Rtau deposits in mice inoculated with PiD sarkosyl-insoluble fractions [45].