In addition, adipocyte-derived hormones such as leptin are associated with increased proliferation of ER-positive ovarian cancer cells, while ERα can be transcriptionally activated through the signal transducer and activator of transcription-3 (STAT3) signaling pathway, suggesting that both ER status and growth promoting properties of adipocytes need to be considered in obese ovarian cancer patients (Choi et al., 2011). This evidence concerns the gene ESR1 and ovarian cancer.