The IKMC targeting vector PG00190_Z_7_B08 was used to insert a construct containing an FRT site, lacZ gene, loxP site, neo gene, FRT site and loxP site upstream of exon 3 and a third loxP site downstream of exon 3. Flp mediated recombination removed the lacZ and neo genes leaving exon 3 floxed. (J:256331)