The TGA stop codon was replaced with the P2A-EGFP-CreERT2 cassette. CreERT2 recombinase and enhanced green fluorescent protein (EGFP) are expressed under the regulatory control of Gfi1 gene elements. This model is a Tamoxifen-inducible Cre mouse, and when crossed with mice containing loxP sites, the offspring mice are expected to undergo sequence recombination between loxP sites mediated by Cre recombinase in Gfi1-positive cells following Tamoxifen induction. In addition to studies of Cre recombinase-mediated gene recombination, this model can also be used for EGFP fluorescent protein tracing studies.