Western blotting of carbonic anhydrase I (CA I), fumarate hydratase (FH), and betaine–homocysteine S-methyltransferase 1 (BHMT) were performed and definitely showed they were down-regulated in the cancer tissues of HCC with PVT, compared to HCC without PVT (Fig. 3). The gene discussed is CA1; the disease is hepatocellular carcinoma.