ESR1 and endometrial carcinoma: “In the TCGA data subset of 539 endometrial carcinomas analyzed, we identified 88 (16.3%) cases with amplifications encompassing or overlapping ESR1. 46.6% of these were histologically defined serous and 75.0% of the tumors with ESR1 amplification were clustered within the serous like copy-number high molecular subtype according to TCGA.