In addition to hormone-dependent breast cancer, antiestrogen medications such as tamoxifen and aromatase inhibitors have shown efficacy in managing conditions such as endometrial cancer and certain types of ovarian cancer.367,368 Although estrogen levels are low in prostate tissue, ER expression has been detected in some prostate cancer patients.369 ER activation is believed to be associated with the proliferation and metastasis of prostate cancer cells.370 Thus, antiestrogen therapy targeting the ER has also been proposed as a new treatment strategy for prostate cancer. The gene discussed is ESR1; the disease is prostate cancer.