FANCA and Friedreich ataxia: And even if this phenotype could be rescued by transduction of the hematopoietic progenitors with a vector expressing the human FANCA cDNA13,67, this mild phenotype could be behind our observations of gene editing efficacy and feasibility using FA mouse cells, in comparison with studies of gene editing that have been done in our laboratory using FA-A human cells that had demonstrated higher targeting efficiencies25,26.