Viltolarsen (NS-065/NCNP-01), a phosphorodiamidate morpholino antisense oligonucleotide, targets the splicing of exon 53 in the dystrophin gene. Viltolarsen can be used for the research of the Duchenne muscular dystrophy (DMD).In Vitro: Duchenne muscular dystrophy (DMD) is one of the most common lethal muscle-wasting disorders affecting young boys caused by mutations in the DMD gene. Exon skipping has emerged as a promising therapy for DMD. Antisense oligonucleotides (AONs) are designed to induce the skipping of exon(s), in order to restore the reading frame, and therefore, allow for dystrophin expression.