A therapeutic approach currently in clinical trial for Duchenne muscular dystrophy. It involves small pieces of DNA called 'molecular patches' which mask a portion of a gene where there is a mistake, or mutation. The name comes from 'exon' which are the segments that genes are divided into. For example, the dystrophin gene (which is affected in Duchenne muscular dystrophy) is divided into 79 exons. It is called 'skipping' because the molecular patch causes the body to ignore or skip-over an exon. For a more detailed explanation please see: What is exon skipping and how does it work?