CA9 and hepatocellular carcinoma: Previous studies reported that vascular endothelial growth factor receptor 2 (VEGFR2) rs7692791, WW domain-containing oxidoreductase (WWOX) rs9926344, carbonic anhydrase IX (CA9) rs1048638, and DICER rs1057035 polymorphisms were positively associated with poor prognosis in HCC patients [11,12,13,14].