The targeting vector was designed to insert a Cre/ERT2 fusion protein into the ATG start codon of the F-box protein 2 (Fbxo2) gene. Specifically, this vector includes (from 5' to 3') a cre/ERT2 fusion gene (Cre recombinase fused to a human estrogen receptor ligand binding domain), a polyadenylation signal, and a loxP-flanked neomycin resistance (neo) cassette. The resulting chimeric mice were bred to a Cre transgenic strain to remove the neo cassette. (J:339364)