ESR1 and serous adenocarcinoma: The majority of serous carcinomas of borderline epithelial ovarian cancerwere ER or PR positive, but in contrast less than 33% of mucinous carcinomas of borderline epithelial ovarian cancerswere ERor PR positive.Furthermore, there was no association between the ER or PR positivity and menopausal status in both malignant and borderline epithelial ovarian cancer.