Interestingly, no significant correlation between MCM3 expression and RFS (p = 0.3, or p = 0.24) or breast cancer-specific death (p = 0.34 or p = 0.74) was observed for neither of the two cohorts (Fig. 2i, j and Fig. 3c, d), suggesting that MCM3 has potential as a predictive marker that can stratify ER+ patients into good and poor responders of adjuvant tamoxifen treatment. Here, ESR1 is linked to breast cancer.