Using RNP composed of two gRNAs surrounding the pathologic GAA(n) region and the Cas9 protein, we efficiently removed the pathologic intronic GAA expansion in CD34+ cells isolated from FRDA patients’ peripheral blood, and demonstrated that gene correction restored frataxin expression, allowed for normal hematopoietic differentiation and mitochondrial function in treated cells, in vitro and in vivo (Rocca et al., 2020). This evidence concerns the gene FXN and Friedreich ataxia.