In the present study, we found a similar phenomenon in that patients with the single hormone receptor–positive subtype had more aggressive clinicopathological features, including larger tumor size, positive lymph node status, distant metastasis, adjusted AJCC sixth edition advanced stage, higher tumor grade, and BC-specific death, than those with the ER-positive/PR-positive subtype, but those with the single hormone receptor–positive subtype had less aggressive clinicopathological features than those with ER-negative/PR-negative subtype. Here, ESR1 is linked to breast cancer.