EGFR and non-small cell lung carcinoma: The human NSCLC cell line A549, which contains three copies of wild-type EGFR [27], was co-transfected with two EGFR-targeting Cas9n vectors and a ssODN (146 nucleotides, sense strand) donor containing a CTG→CGG mutation (boxed in Fig 1A) flanked by sequences homologous to the EGFR target site.