Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are characterized pathologically by the accumulation of cytoplasmic inclusions in affected neurons and glial cells that, in 97%–98% of cases, stain positive for TAR-DNA binding protein 43 (TDP-43; Neumann et al., 2006). The gene discussed is TARDBP; the disease is frontotemporal dementia.