For bone metastasis, the results showed that the patients with HR+/HER2− had a significantly higher probability than those with the other three BCS (HR+/HER2+ vs HR+/HER2-: OR 0.699, CI% 0.584-0.765; HR-/HER2+ vs HR+/HER2-: 0.355, CI% 0.301-0.419; HR-/HER2- vs HR+/HER2-: 0.323, CI% 0.281-0.372) (Table 3). The gene discussed is ERBB2; the disease is bone metastasis.