Model Description: A CreERT2-pA expression cassette was knocked into the Axin2 gene start codon site. As Axin2 is an intracellular protein, it is essential for identifying a surface marker for stem cell purification. When these Axin2-CreERT2 mice are bred with mice containing a loxP-flanked sequence of interest, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the flanked sequences in Axin2 expressing cells.