MAPT and frontotemporal dementia: The spectrum of FTD syndromes is associated with a diverse range of neuropathological processes, including proteinopathies predominantly involving tau and TDP-43 accumulation.3 4 A modest number of FTD patients present with rarer proteinopathies, including ubiquitin accumulations, as well as fused-in-sarcoma (FUS) pathologies.5 6 Disease progression is further influenced by cellular processes such as neuroinflammation.7