TARDBP and proteostasis deficiencies: Our findings highlight the importance of characterizing the protein composition of aggregates in order to understand the underlying pathological mechanisms and suggest that the co-localisation of hnRNP E2 with TDP-43 in inclusions may have implications in the pathogenesis of a subset of FTLD-TDP cases - which could even be considered as a subtype in future classifications of FTLD-TDP-43 proteinopathies.