A loxP and FRT flanked neo cassette was inserted in intron 6 and a loxP site was inserted in intron 10 via homologous recombination. Recombinase mediated recombination removed the neo cassette and exons 7 - 10 (1.7 kb) creating a frameshift and premature stop codon at the start of exon 11. (J:264168)