Abstract
CDK4/6 inhibitors exert effective anti-tumor effects by blocking the cell cycle and, as a result, have become vital in the systemic treatment of malignant tumors. Previous research has indicated that CDK4/6 inhibitors not only exert effects on the cell cycle but also have regulatory roles in tumor immunity, although the research findings are controversial. This study comprehensively summarizes the molecular mechanisms by which CDK4/6 inhibitors activate or suppress anti-tumor immunity and reveals the dual effects of CDK4/6 inhibitors on influencing interferon signaling, mediating senescence, and altering certain immune cells. In addition, the results of clinical trials of CDK4/6 inhibitors combined with immunotherapy are thought-provoking, with the severe adverse events that occur after treatment being the main factor affecting their therapeutic effect. Therefore, the future direction of this combined treatment strategy deserves further exploration.