CDK4 and breast cancer: Therefore, we conducted this network meta-analysis to investigate the comparative efficacy and safety of various combinations of three CDK4/6 inhibitors (abemaciclib, palbociclib, and ribociclib) and two endocrine therapies (AI and fulvestrant) in patients with HR+/HER2- metastatic or advanced BC, with the aim of providing evidence-based recommendations for clinical decision-making.