To investigate whether gene targeting was feasible in FA cells we focused on the most frequent FA complementation group, FA-A (Casado et al, 2007; Auerbach, 2009), and investigated the possibility of inserting the therapeutic transgene in a safe harbor locus of the human genome—the AAVS1 locus (Lombardo et al, 2011). The gene discussed is PPP1R12C; the disease is Friedreich ataxia.