HIF1A and hepatocellular carcinoma: The median O2 partial pressure in HCC is 6 mm Hg compared with 30 mm Hg in normal liver (Vaupel et al, 2007), and the homeostatic response to the intratumoral hypoxic environment is mediated by hypoxia‐inducible factor (HIF‐1), consisting of HIF‐1α and HIF‐1β subunits (Koh & Powis, 2012).