However, it should be noted that a recent study from Norway that included women diagnosed with BC in 1995 or later demonstrated that the cumulative risk of death from BC was 22.3% after five years for ER expression < 1% and 8.3% for both the ER-low-positive and ER expression ≥ 10% groups, meaning that there was no apparent difference in the risk of death from BC between the ER-low-positive and ER expression > 10% groups [37]. Here, ESR1 is linked to breast cancer.