Abnormal accumulation of TAR DNA-binding protein-43 (TDP-43) is a pathological hallmark of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease characterized by a selective loss of motor neurons, and a subtype of frontotemporal lobar degeneration (FTLD-TDP)1. The gene discussed is TDP1; the disease is amyotrophic lateral sclerosis.