RANGAP1 and amyotrophic lateral sclerosis: Considering the recent finding that aberrant SG assembly can disrupt nucleocytoplasmic transport [59], we examined the cellular distribution of RanGAP1, an essential regulator of nucleocytoplasmic transport that has been shown to be mislocalized in Drosophila expressing the G4C2 repeat, as well as in iPSCs and motor cortex from a C9orf72 ALS patient [60].