ERG and proximal spinal muscular atrophy: SSOs can promote the inclusion of desirable exons (e.g. TOES, targeted oligonucleotide enhancers of splicing,29) or induce exon skipping as illustrated by our own ERG exon 7b SSO14 and Eteplirsen.27 Another success story is Nusinersen, an FDA-approved ASO (Spinraza, Biogen) that is used to treat spinal muscular atrophy (SMA).