TARDBP and amyotrophic lateral sclerosis: In addition, protein aggregation is commonly observed in other neurodegenerative disorders, such as α-synuclein in Parkinson disease (PD) [25], and TDP-43 in ubiquitin-positive frontotemporal lobar degeneration (FTLD-U) and amyotrophic lateral sclerosis (ALS) [26].