CA9 and hepatocellular carcinoma: To assess HIF-1α transcriptional activity, we measured the expression of HIF-1α-dependent genes: vascular endothelial growth factor A (VEGF-A), glucose transporter 1 (GLUT-1), and carbonic anhydrase 9 (CA9) in 20 PVTT(−) and 20 PVTT(+) primary HCC samples.