ESR1 and breast cancer: The 10-year absolute risks of breast cancer death for ER-positive, tamoxifen-treated patients were 3.7% (95% CI 1.9% to 5.4%), 5.9% (95% CI 3.0% to 8.6%), and 12.9% (95% CI 7.9% to 17.6%) for those in the low-, intermediate- and high-risk groups, respectively, when classified by MGI+HOXB13:IL17BR.