Given that p62 changes in the hippocampus and cerebellum might be pathognomic for expansions in C9ORF72[9,11], we immunostained sections of temporal cortex (with hippocampus) and cerebellum in 200 pathologically confirmed cases of AD in order to ascertain to what extent an expansion in C9ORF72 might be present in AD, particularly in those cases with (extensive) TDP-43 pathology, since it is possible that such cases, in the context of a clinical picture resembling AD, might be ones with undisclosed/unrecognised FTLD. Here, TARDBP is linked to Alzheimer disease.