ARG1 and hepatocellular carcinoma: Betaine–homocysteine S-methyltransferase 1 (BHMT), isovaleryl-CoA dehydrogenase (IVD), short-chain specific acyl-CoA dehydrogenase (CRAT) and arginase-1 were all down-regulated in cancer tissues of HCC without PVT and further deceased in the cancer tissues of HCC with PVT.