TARDBP and frontotemporal dementia: TAR DNA-binding protein of 43 kDa (TDP-43) proteinopathy was first discovered in the context of frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS), where a substantial number of participants presented at death with ubiquitinated inclusions but without a tauopathy which might have explained their clinical presentation.