ESR1 and breast cancer: The prognostic and predictive role of Recurrence Scores in node-positive breast cancers was evaluated by RxPonder (A Clinical Trial RX for Positive Node, Endocrine Responsive Breast Cancer) [57], a prospective clinical trial randomizing women with ER+, node positive (1–3 positive lymph nodes) and Recurrence Scores of 0–25 to chemotherapy plus endocrine therapy vs. endocrine therapy alone.