Two-day-old Pompe mice injected with virus targeting Gys1 mRNA were partially corrected for the buildup of glycogen measured 4 weeks later.31 We have extended the concept of SRT for Pompe disease by developing a systemically-deliverable peptide conjugated morpholino (GS-PPMO) the mechanism of action for which is based on exon skipping. This evidence concerns the gene GYS1 and glycogen storage disease II.