EPAS1 and hepatocellular carcinoma: It was found that the expression of HIF-1α protein was markedly increased in HCC tissues, without significant changes for HIF-2α, or c-myc, or the levels of HIF-1α mRNA in HCC and normal control (Figure 5A), suggesting that HIF-1α accumulation in HCC is likely due to enhanced protein stability rather than increased transcription.