Glutamic acid codon 50 (GAG) in exon 2 was changed to lysine (AAG) (c.148G>A p.E50K) using an sgRNA and an ssODN template with CRISPR/Cas9 technology. This mutation, in the EMO (NF kappa B essential modulator) domain of the encoded peptide, replicates the same human mutation associated with normal-tension glaucoma (NTG).