The remaining 13 patients (31 %) with MND (patients #26, 30–41) (but none with FTD + MND and only 1 with FTD (patient #79 with PNFA) displayed a ‘significant degree of tau pathology’, as defined by the presence of a few to many neurofibrillary tangles and/or neuropil threads in several brain regions, usually with all 3 tau antibodies and again usually to a similar extent and with a similar distribution. The gene discussed is MAPT; the disease is frontotemporal dementia.