models, but the pathophysiological basis is only partially defined. We have used cre-
loxPtechnology in combination with gene targeting to perform global, β cell-, and hepatocyte-
specific gene knock-outs of this enzyme in mice. Gene targeting was used to create a triple-
loxed gk allele, which was converted by partial or total Cre-mediated recombination to a
conditional allele lacking neomycin resistance, or to a null allele, respectively. β cell-and …