Patients with hormone receptor positive and human epidermal growth factor receptor 2 negative (HR+/HER2−) disease were reported to have more bone metastasis, patients with HR−/HER2+ tumors had more liver metastasis, whereas brain and lung metastasis were more likely to occur in HR−/HER2− patients (5, 6). The gene discussed is ERBB2; the disease is bone metastasis.