The 3'UTR was replaced with A loxP site, unstable mouse Fos 3'UTR, neomycin resistance cassette, loxP site and stable bovine GH 3'UTR. Cre-mediated recombination removed the Fos 3'UTR and selection cassette. QRT-PCR confirmed increased transcript expression in the kidney of 40 week old mice. (J:230491)