As we expected, the results showed the most common combination metastasis was “single bone metastasis”, with the percentage of 52% in patients with HR+/HER2-, 35.2% in patients with HR+/HER2+, 20.7% in patients with HR-/HER2+, 25.8% in patients with HR-/HER2-, respectively. Here, ERBB2 is linked to bone metastasis.