An FRT flanked neo cassette with a 3' loxP site was inserted between exon 3 and 4, and an additional loxP site was inserted between exons 6 and 7. Flp-mediate recombination to remove the neo cassette was accomplished using Tg(ACTFLPe)9205Dym. Insertion was confirmed by Southern blot analysis and PCR genotyping.