CRISPR/cas9 endonuclease-mediated genome editing is used to insert two nucleotide missense mutations in exon 5 of the gene. The mutation results in an amino acid substitution at position 153 altering asparagine to serine (N153S; AAT to TCT). The STING N153S mutation is analogous to the N154S mutation in human TMEM173. N154S is associated with (STING)-associated vasculopathy with onset in infancy (SAVI). (J:251372)