A transgenic construct containing the cre/ERT2 (cre recombinase and estrogen receptor 1 tamoxifen binding domain fusion gene) under the control of the rat Eno2 (enolase 2, gamma, neuronal) promoter, was injected into fertilized FVB/N mouse eggs. Founder line 1 was subsequently established. The mice were crossed to mice on a mixed background, containing C57BL/6, 129, and ICR.