FUS and proteostasis deficiencies: Given this genetic heterogeneity, it is not surprising that the neuropathology underlying clinical FTD is also heterogeneous: TAR-DNA-binding protein-43 (TDP-43) proteinopathies, especially types A or B, are the commonest causes of genetic FTD, followed by tauopathies, fused-in-sarcoma (FUS) pathologies, and other rarer proteinopathies [79].