Until now, there are three FDA approved AAV gene therapies, Luxturna, Zolgensma, and Hemgenix, for treatments of a rare retinal disorder (RPE65 mutation-associated retinal dystrophy), spinal muscular atrophy, and hemophilia B, respectively.51 The observation that there are nearly ten times the number of ODDs for AAV gene therapies compared to approved products reflects a massive expansion in the pipeline for new gene therapies, which is expected to continually grow. This evidence concerns the gene RPE65 and hemophilia B.