An N-terminal FLAG tag was added after the start codon within exon 2 and a single loxP site was inserted in intron 1 within the 5' UTR. A loxP flanked neo was inserted within intron 5. The selection cassette and exons 2-5 were removed by dre mediated recombination. Northern and Western blotting of various organs demonstrated that there was no transcription or translation. (J:158394)