It is clear that the earlier treatment is initiated the better in terms of photoreceptor rescue, and more efficient transduction of the outer retina will be essential to deliver a more substantial augmentation of RPE65 and sustain the visual cycle.39 Finally, although the lack of functional wild-type protein is considered to be a major factor driving retinal degeneration in LCA, correcting RPE65 gene expression on its own might not be sufficient and additional neuroprotective strategies might have to be provided concurrently. The gene discussed is RPE65; the disease is Leber congenital amaurosis.