As both 3 R tau and 4 R tau isoforms were showed to be present in the sarkosyl insoluble fractions of the FTD-tau S320F patient brain24, we directly tested a concentration titration of 3 R tauRD and 4 R tauRD in a ThT fluorescence assay (Supplementary Fig. 1c). The gene discussed is MAPT; the disease is frontotemporal dementia.