HDAC9 and pancreatic neoplasm: Previous studies have reported that histone deacetylases (HDACs) are overexpressed in PC, and inhibiting HDACs could induce apoptosis and curb metastasis.17 A promising novel HDAC inhibitor, CG200745, can inhibit pancreatic cancer cell proliferation by increasing tumor suppressor genes and decreasing ABCC3/ABCC4 genes.18 Paradoxically, HDAC inhibitors can enhance ABC transporters, thereby attenuating certain drugs.19 Accordingly, HDAC inhibitors could be combined with inhibitors of ABC transporters in PDAC.