TARDBP and amyotrophic lateral sclerosis: Considering that TDP-43-positive inclusions are detected in various neurodegenerative disorders other than ALS and FTLD-TDP, further investigation is required to elucidate whether TDP-43 inclusions primarily play a crucial role in triggering these disorders or if they are secondarily induced by the other primary aggregating proteins such as tau and α-synuclein.