The first FDA-approved gene therapy for IRD, specifically RPE65-associated vision loss,2, , –5 has motivated the development of many more gene therapy approaches for treating IRDs, with several currently being tested in clinical trials.6, , , , , –12 However, gene therapy will not be the cure for all forms of IRDs; for example, those that cause very rapid and early onset neurodegeneration may not have sufficient living cells remaining by the time a gene therapy vector is available. The gene discussed is RPE65; the disease is respiratory distress syndrome in premature infants.