In this issue of the Journal, two groups of investigators —Bainbridge et al.1 and Maguire et al.2 — describe thefirst results of separate clinical trials investigating theshort-term safety and preliminary efficacy of gene therapy forLeber's congenital amaurosis. Both groups present short-termdata (12 months and 5 months, respectively) on three patientswith Leber's congenital amaurosis in each study; the patientswere enrolled in trials of recombinant adeno-associated viraldelivery of the human retinal pigment epithelium-specific 65-kDaprotein gene (RPE65), which was administered as a subretinalinjection during vitrectomy.