RanGAP, a key regulator of nucleocytoplasmic transport, was found to bind to both the G4C2 RNA and the DPR protein poly(GA) thereby causing defective nucleocytoplasmic transport in Drosophila and mouse models of C9orf72-ALS and iPSC derived neurons (Zhang et al., 2015, 2016). This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.