CDK4 and neoplasm: Agostinetto E and Gao HF evaluated IDFS efficacy indicators in 12,647 patients with HR+/HER2− EBC and concluded that CDK4/6 inhibitors combined with ET had more IDFS benefit independent of tumor size, TNM stage, tumor stage, nodal stage, histologic grade, prior neoadjuvant chemotherapy, age, race, and menopausal status, but all had low quality of evidence.