Following Trastuzumab treatment, no difference was seen between subtypes in bone metastasis (OR 0.958, 95% CI 0.17–5.60; p = 0.96) but a significantly lower risk in brain metastasis is seen in the Luminal B HER2 cancers (OR 0.19, 95% CI 0.03–0.85; p = 0.041). The gene discussed is ERBB2; the disease is bone metastasis.