Cletus A. et al. reported that ER+/HER2+ and ER-/HER2+ breast cancers had different metastasis patterns, and that the OS of patients with the ER+/HER2+ signature was better than that of patients with the ER-/HER2+ signature, particularly those treated with anti-HER-2 therapy [70]. The gene discussed is ESR1; the disease is breast cancer.