CDK4 and breast cancer: By regulating the G1/S phase, cyclin‐dependent kinase 4 (CDK4) and CDK6 may participate in breast cancer cell metastasis,6 high Cyclin D1/CDK4 complex levels increase glioblastoma cell metastasis,7 and RUNX2 promotes PCa cell bone metastases and tissue invasion of C4‐2B and LNCap PCa cells.8