Considering that current HDAC inhibitors suffer from long-term safety concerns, poor pharmacokinetic profiles, and mixed results in earlier ovarian cancer trials (Jones et al., 2016; Khabele, 2014; West and Johnstone, 2014), these results point to an exciting opportunity to combine them with chemotherapy and meanwhile look upon PAX8 regulon as promising biomarkers for improved treatment outcomes in systematic or intraperitoneal settings. The gene discussed is HDAC9; the disease is ovarian cancer.