CEP290 and Leber congenital amaurosis: A clinical trial of CRISPR/Cas9 is underway to test subretinal delivery of an AAV5 vector encoding two guide RNAs and Cas9 designed to delete a mutation in the CEP290 gene associated with Leber’s Congenital Amaurosis (LCA), a common cause of childhood blindness (ClinicalTrials.gov Identifier: NCT03872479), (Maeder et al., 2019).