TP53 and osteosarcoma: Osx-Cre-mediated deletion of p53 and Rb in both Osx-Cre+ p53fl/+ pRbfl/+ and Osx-Cre+ p53fl/fl pRbfl/fl mice resulted in osteosarcoma, and the latency of the disease could be delayed using a doxycycline diet [40].