This webinar will explore the biological and clinical rationale for CDK4/6 inhibition in HR+/HER2− breast cancer, examining differences across CDK4/6 inhibitors and emerging therapeutic approaches, including oral SERDs. It will address how CDK4/6 inhibition may influence tumour biology, focusing on senescence, dormancy, recurrence and immune modulation in both early and advanced disease. The discussion will connect preclinical and mechanistic evidence with clinical data, highlighting the rationale for combining CDK4/6 inhibitors with endocrine therapy and the implications for treatment outcomes and clinical decision-making.