Brain tissues from six individuals with different types of tauopathy (AD, CTE, Pick’s disease [PiD], progressive supranuclear palsy [PSP], corticobasal degeneration [CBD], and frontotemporal dementia and Parkinsonism linked to chromosome 17 with a P301L mutation in MAPT) were used for the extraction of sarkosyl-insoluble tau seeds of known structure. The gene discussed is MAPT; the disease is Alzheimer disease.