The first vector introduced a loxP site upstream of the Gpr89 gene. The second vector introduced a loxP site downstream of the Prkab2 gene. Homologous recombinant clones were isolated and the 0.8 megabase region on mouse chromosome 3 between the loxP sites was removed using in vitro Cre-mediated recombination. This deletion corresponds to human chromosome region 1q21.1. (J:147112)