CDK4 and prostate cancer: By up-regulating the cycle-related factors CDK-4, CDK-6, and Cyclin D1 and down-regulating the apoptosis-related factors Caspase 3, Caspase 8, Caspase 9, and BAX, RTDP can arrest the cell cycle at G0/G1 phase and induce apoptosis, indicating that RTDP has significant anti-prostate cancer DU145 cells activity.