The two major primary liver cancers in adults are hepatocellular carcinoma and cholangiocarcinoma. These tumors rapidly outgrow their vascular supply and become hypoxic, resulting in the production of hypoxia inducible factors. Recently, interest has grown in the regulators of these factors. Several reports have been published describing the role of prolyl hydroxylase domains - the key oxygen sensor responsible for the degradation of hypoxia inducible factors - in tumor progression and vascularisation. The effect of prolyl hydroxylase domain 2 on the pathogenesis of liver cancer has never been studied.