A single loxP site was inserted into intron 2 and an FRT-flanked neomycin/kanamycin selection cassette with a second loxP site was inserted into intron 6. Exons 3 through 6, encoding amino acids 88-220, were excised by cre recombinase mediated excision. This is predicted to result in the incorporation of 19 novel amino acids followed by a premature stop codon. (J:164059)