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. The gene discussed is HDAC9; the disease is pachyonychia congenita.