HL-60, Jurkat and K-562 leukemia cells were co-transfected with plasmids expressing Cas9-NLS and an XPO1 targeting single guide RNA together with a 135 bases single-stranded oligodeoxynucleotide repair donor template containing the TGT to TCA mutation in addition to 3 silent mutations (Figure 1a). This evidence concerns the gene XPO1 and leukemia.