All FTD-GRN and 7 out of 11 FTD-C9orf72 cases exhibited type A TDP-43 inclusions [35], with the rest exhibiting type B. The severity of TDP-43 neuronal cytoplasmic inclusions in frontal grey matter (Fig. 1A-D) or glial cytoplasmic inclusions in frontal white matter (Fig. 1E) did not differ significantly between FTD-GRN and FTD-C9orf72 cases (Fig. 1F-G), nor did the severity of TDP-43-positive dystrophic neurites (Fig. 1H-I), indicating that the FTD-GRN and FTD-C9orf72 cases are well-matched neuropathologically. This evidence concerns the gene C9orf72 and frontotemporal dementia.