A vector was used to insert IRES-Cre-ERT2 downstream of the stop codon in exon 14. Transient FLP-recombinase excised a FRT-floxed neo 3' to the Cre. ES cell clone XF136.64 was injected into blastocysts to generated mice. Southern blot confirmed recombination. RT-PCR indicated bicistronic expression was only present in the liver of mutants. Immunohistochemical analysis of liver using an anti-Cre antibody showed that Cre is expressed in most, if not all, hepatocytes. (J:92298)