HSP90AA1 and frontotemporal dementia: Meanwhile, in the case of FTD, mutations on chromosome 17 in human tau isoforms lead to one of its forms, i.e., FTDP-17 (FTD and Parkinsonism related to chromosome-17), also ubiquitinated and hyperphosphorylated; TDP-43 have been found to form toxic pathological aggregates, and as TDP-43 co-immunoprecipitates with HSP70 and HSP90, knockdown of these heat shock proteins can lead to its hyperphosphorylation with an increase in its C-terminal [85,86,87,88,89,90].