FANCA and Friedreich ataxia: Due to the fact that the most frequent complementation group in FA patients is FA-A (60–70%), and given that mutations in FANCA are highly heterogeneous20–22, a therapeutic strategy to precisely insert a therapeutic FANCA expression cassette into a safe harbor locus23,24 would be applicable to all FANCA mutations25,26 and could be in principle extended to other FA subtypes.