Using CRISPR/cas9 technology an IRES enhancer sequence, a CreER(T2) fusion gene, and a rabbit globin polyadenylation (rGpA) termination sequence were inserted immediately downstream of the LBH domain containing 2 locus of the Lbhd2 gene on chromosome 12. The construct was electroporated into C57BL/6JJcl-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts, and chimeric mice were bred with C57BL/6JJcl for germline transmission. (J:315131)