ESR1 and breast cancer: High expression of SLC39A7 was significantly associated with worse OS in ER positive patients [HR = 4.57(1.23–16.93), P=0.013, Figure 5C], but no significant correlation was found between SLC39A7 expression and OS of patients with ER negative BC [HR = 0.48(0.17–1.36), P=0.16, Figure 5D].