A targeting vector was designed to insert a loxP site upstream of exon 5, followed by a frt-flanked neomycin resistance (neo) cassette, and a second loxP site downstream of exon 6 of the a disintegrin-like and metallopeptidase (reprolysin type) with thrombospondin type 1 motif, 18 (Adamts18) gene. (J:181091)