In early-stage breast cancer, the monarchE trial established the invasive disease-free survival (iDFS) benefit of the addition of two years for adjuvant abemaciclib to endocrine therapy in HR-positive, HER2-negative patients with node-positive disease and a high risk of recurrence, defined as ≥four pathological involved lymph nodes (LNs) or one to three LNs and either tumor size ≥ 5 cm or grade 3 [6,7]. The gene discussed is ERBB2; the disease is breast cancer.