SRSF1 and amyotrophic lateral sclerosis: First, we and others have previously shown that several RNA binding proteins (RBPs) such as Serine/Arginine-Rich Splicing Factor 1 (SRSF1), Serine/Arginine-Rich Splicing Factor 2 (SRSF2) and Nucleolin (NCL) bind (G4C2)n RNA, and co-localise with (G4C2)n RNA foci in C9ORF72-ALS cells (24,28).