C9orf72 and amyotrophic lateral sclerosis: As VPS4 is a AAA-ATPase that facilitates the removal of NPC and NE components from the nucleus and nuclear membrane [23, 29, 32–34], we hypothesized that increased nuclear VPS4 expression might also functionally contribute to NPC injury in C9orf72 ALS/FTD and sALS neurons.