This approach draws on the gene therapy field in which AAV vectors encoding sequences of deficient proteins are given by various routes to induce sustained expression and provide functional improvement or prevention of progression.4, 5 For example, intramuscular administration of a recombinant AAV (rAAV) vector encoding the alpha-1 antitrypsin (AAT; also known as serpin family A member 1) gene in patients with AAT deficiency induced sustained protein expression for more than 5 years.6 This evidence concerns the gene SERPINA1 and alpha 1-antitrypsin deficiency.