Although the cytoplasmic mislocalization and aggregation of TAR DNA-binding protein-43 (TDP-43) is a common histopathological feature of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia disease (FTD) spectrum, little is known about the composition of these aggregates and their involvement in the disease process. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.