A loxP site was inserted 3' of Hoxd11 and a Hoxd9/lacZ/loxP transgene ( Tg(Hoxd9/lacZ/neo)4Ddu) was inserted 26 kb upstream of the Hoxd13 start site via homologous recombination. Mutant animals were mated to cre deleter line Tg(CMV-cre)1Ipc to delete the entire region between the 2 loxP sites, which includes Evx2, Hoxd13, Hoxd12, and Hoxd11. (J:54543)