Transactive response DNA binding protein of 43 kDa (TDP-43) is a major component of cytoplasmic aggregates in neurons and glia in most patients with amyotrophic lateral sclerosis (ALS) and in a subgroup of patients with frontotemporal lobar degeneration with TDP-43 (FTLD-TDP) [1–3]. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.