CRISPR-targeting introduced at the end of the coding sequence in exon 8 a GSG (Gly-Ser-Gly)-linker, porcine teschovirus-1 2A (P2A) peptide, SV40 virus NLS, P1-like transducing phage D6 dre recombinase gene, and puromycin resistance cassette flanked by FRT sites (FRT/F3/F5). Flp-mediated recombination removed the selection cassette.