CDK4 and glioblastoma: It is reported that co-deletion of CDKN2A and CDKN2C confer Palbociclib-sensitivity in glioblastoma (Wiedemeyer et al. 2010) and soft tissue sarcoma, demonstrating that amplification of CDK4 benefits from the CDK4/6 inhibitor (Mangat et al. 2018).