C9orf72 and amyotrophic lateral sclerosis: Antisense oligonucleotides (ASOs) targeting the C9orf72 repeat expansion suppress RNA foci formation, attenuate sequestration of specific RNA-binding proteins and reverse gene expression alterations in C9orf72 ALS motor neurons derived from IPSCs (Donnelly et al., 2013; Lagier-Tourenne et al., 2013).