ESR1 and breast cancer: Within the ER-positive subgroup, SRAP is as a poor prognostic marker for BCSS and RFS in the subset of node-negative and young breast cancer patients (n = 60, HR = 8.616, P = 0.006 and HR = 3.566, P = 0.011, respectively), but not in older or node positive patients (Figures 8a, b).