Although we hypothesized that patients with tumors classified as ImPrint+ might be younger and more commonly premenopausal/perimenopausal than those with ImPrint– tumors, because of previously reported association between higher immune infiltration and premenopausal status in women with low genomic risk, ER+HER2– cancers,27 we observed no significant difference in age, menopausal status, or race/ethnicity between ImPrint± classes (Appendix Table A1). Here, ESR1 is linked to cancer.