An open-labeled phase III clinical trial (monarchE, NCT03155997) (Study Details Endocrine Therapy With or Without Abemaciclib LY2835219 Following Surgery in Participants With Breast Cancer ClinicalTrials.gov, 2023) assessed the effectiveness and safety of abemaciclib in patients with high-risk, node-positive HR+/HER2– breast cancer. The gene discussed is ERBB2; the disease is breast cancer.