To examine the importance of the RP-Mdm2-p53 pathway in APT121-induced prostate cancer, we generated APT121;Mdm2+/+ and APT121;Mdm2C305F/C305F mice and non-tumorigenic control Mdm2+/+ and Mdm2C305F/C305F mice. The gene discussed is MDM2; the disease is prostate cancer.