ESR1 and ovarian mucinous adenocarcinoma: It has previously been shown that the stroma of mucinous cystic ovarian neoplasms similarly expresses strong reactivity for estrogen receptor (ER) and progesterone receptor (PR), possessing occasional luteinized stromal cells and similar overexpression of steroidogenic markers and enzymes in ovarian mucinous adenocarcinomas; it has been suggested that SF-1 overexpression may activate aromatase and promote estrogen biosynthesis.