CDK4 and cancer: Another EGFR inhibitor, Lapatinib, along with the CDK4/6 (cyclin-dependent kinase 4/6) inhibitors Ribociclib, Palbociclib, and Abemaciclib, has been FDA-approved in breast cancers (https://www.cancer.org/cancer/breast-cancer/treatment/targeted-therapy-for-breast-cancer.html).