ESR1 and ovarian carcinoma: The tumor status of estrogen and progesterone receptors, which have already been shown to play a prognostic role, has previously been evaluated as predictive markers of response to endocrine therapy, including ERα expression or an ER histoscore > 200.8,9,19,33 However, although a large proportion of epithelial ovarian cancers express the ERα receptor, this factor alone does not seem to be sufficient to predict response to hormone therapy.