HIPK2 and hepatocellular carcinoma: The double HIF-1α and HIPK2 knockout greatly counteracted the tumor growth caused by the HIPK2 knockout, suggesting that the effect of HIPK2 depletion on HCC progression was mediated by HIF-1α and by the HIF-1-induced angiogenesis [37], further strengthening the effect of the HIPK2/HIF-1α balance.