In multivariable analysis, patients with ER+/LN+/HER2− CCND1-amplified tumours were found to have worse 15-year BCSS (HR = 2.07, 95% CI, 1.12–3.83), and comparable trends were noted in luminal A (HR = 1.97, 95% CI, 0.95–4.08) and luminal B (HR = 2.01, 95% CI, 0.94–4.30) subgroups. The gene discussed is CCND1; the disease is neoplasm.