Together, these studies have validated the potential of CDK6 as an antitumor therapeutic target, making the study of CDK4/6 inhibitors to treat malignant tumors an area of active research; indeed, the CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib have now been approved by the U.S. Food and Drug Administration. This evidence concerns the gene CDK6 and cancer.