First, a single guide RNA (5'-TGAACATTCTGACAAGACCC-3') was designed to target sequences in exon 2. Next, a DNA oligo for homology directed repair (HDR) was designed to target a 33 bp insertion (BamHI site, Flag tag sequence and STOP sequence) into exon 2 that introduced a premature stop codon at amino acid 93 (P83delinsGSDYKDDDDK*). (J:281519)