By screening for tau pathology in 201 autopsy‐confirmed cases of frontotemporal lobar degeneration with TDP‐43 pathology (FTLD‐TDP), we found 85 patients (42%) with ageing‐related tau astrogliopathy (ARTAG) 72 (36%) with primary age‐related tauopathy (PART), 45 (22%) with argyrophilic grain disease (AGD) and 2 (1%) with corticobasal degeneration (CBD). This evidence concerns the gene MAPT and argyrophilic grain disease.