Palbociclib, a CDK4/6 inhibitor, is currently approved for advanced breast cancer and in phase III clinical trials (65); P276-00, a selective CDK4 inhibitor (79.7% cytotoxicity), has shown anti-proliferative effects against other cancers (66), but too has not been assessed in neuroblastoma. The gene discussed is CDK4; the disease is neuroblastoma.