A loxP site was inserted upstream of exon 10. An FRT-flanked neomycin resistance cassette with a 5' loxP site was inserted downstream of exon 12. Flp-mediated recombination removed the selection cassette and left exons 10 through 12 floxed. Cre-mediated recombination removed exons 10 through 12. (J:213338)