This study found that the black-white difference in breast cancer-specific mortality was observed for women diagnosed with luminal A breast cancer, but not for those diagnosed with basal-like (ER-/PR-/HER2- plus HER1+ and/or CK 5/6+) breast cancer (age-, date of diagnosis-, and stage at diagnosis-adjusted HR, 1.9; 95% CI, 1.3 to 2.9 and HR, 1.3; HR, 0.8 to 2.3 for luminal A and basal-like breast cancer, respectively) [5]. Here, ESR1 is linked to breast cancer.