In the HER-2(+) subgroup, the clinical outcome of ER(-)/PR(+) had a trend toward improvement, which may have a better prognosis than breast cancer with other hormone receptor phenotypes, indicating that ER(-)/PR(+)/HER-2(-) tumors are aggressive, if combined with HER-2(+), the clinical prognosis can be improved. Here, ESR1 is linked to breast cancer.