MYC–HOXB7–HER2 predicts clinical outcome in breast cancer patients treated with tamoxifen. MYC–HOXB7–HER2 predicts clinical outcome in breast cancer patients treated with tamoxifen. The Kaplan–Meier plots of overall survival (OS) probability in endocrine therapy–treated breast cancer patients with ER-positive tumors (n = 1,208) expressing (A) HOXB7, (B) HOXB7 and HER2, and (C) HOXB7, HER2, and MYC. Kideok Jin et al. Cancer Discovery 2015;5:944-959 ©2015 by American Association for Cancer Research