KOMP targeting vectors PG00105_X_1_G09 and PG00105_X_1_E04 were used to create a knockout-first conditional-ready reporter allele. The vector places an FRT site, splice acceptor site, IRES, lacZ cassette, loxP site, neomycin resistance gene cassette, second FRT site and second loxP site into intron 2 and a third loxP site into intron 3. Exon 3 and the neo cassette were deleted through subsequent cre-mediated recombination. (J:298652)