More recently, nucleocytoplasmic transport has moved to the forefront of ALS pathobiology due to nuclear transport defects in numerous model systems expressing either the C9orf72 repeat expansion or dipeptide repeat proteins (DPRs)44–46 as well as in cells expressing c-terminal fragments of TDP-4347. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.