The targeting vector was designed to insert an FRT-flanked neomycin resistance (neo) cassette and a loxP site upstream of exon 2. A second loxP site was inserted downstream of a mutated exon 3. Exon 3 was altered to contain three amino acid substitutions: proline to leucine (P64L), lysine to glutamate (K72E), and isoleucine to histidine (I73H) to obtain the murine orthologue of human CXCL4L1. Flp-mediated recombination removed the neo cassette. (J:270132)