Fig. 2.

Cre activity in the CreERT2 fusion protein is inducible by 4-OH-tamoxifen. In the absence of tamoxifen, CreER is bound to Hsp90 and located in the cytoplasm. Tamoxifen preferentially binds to the Estrogen Receptor (ER), displacing Hsp90 and inducing translocation of CreER to the nucleus, hence activating Cre.