HDAC inhibitors employed alone or in combination with chemotherapy have been studied in ovarian and endometrial cancer clinical trials (NCT00772798, NCT00976183, NCT00993616, and NCT03018249), including our own group’s analysis of entinostat in a surgical window of opportunity trial in endometrial cancer [8, 15, 16]. The gene discussed is HDAC9; the disease is endometrial cancer.