Arginine codon 1278 (CGA) was changed to proline (CCA) (p.R1278P) using an sgRNA and an ssODN template with CRISPR/Cas9 technology. The mutation is the equivalent of the human c.3827G>C, p.Arg1276Pro mutation associated with neurofibromatosis 1 (NF1). (J:324999)