Embryos were injected with guide RNA targeting exon 2 and Cas9 nuclease. Sequencing of several mice revealed an animal carrying the deletion of a single adenine nucleotide in this signal peptide coding region (CGTCTCCCTTCTCCCACTGATA -> CGTCTCCCTTCTCCCACTG*TA) which created a frameshift and premature stop codon. (J:250608)