FUS and amyotrophic lateral sclerosis: Indeed, RNA transcription, splicing, transport, stability, and translation, are affected in ALS motor neurons by both dysfunctional mutant TDP-43 and FUS, two RNA-binding proteins (RBPs) with established roles in the control of RNA metabolism, as well as by GGGGCC (G4C2) hexanucleotide repeat expansions (HRE) in the first intron of the C9orf72 gene, which affect RNA processing by an RNA-mediated gain-of-function mechanism [11,12].