TARDBP and amyotrophic lateral sclerosis: Approximately 90% of ALS cases are sporadic; however, its pathogenesis remains unknown.1,2 TAR DNA-binding protein 43 (TDP-43) was identified as a major component of the ubiquitinated cytoplasmic inclusion bodies in ALS motor neurons.3,4 Although TDP-43 is a nuclear protein, it disappears from the nucleus in degenerating ALS neurons.