HIF1A and neoplasm: Hypoxia is a feature of many tumors including HCC, and the ability of tumor cells to adapt to reduced oxygen and nutrient supply is vital for their survival.3 Hypoxia-inducible factor-1 (HIF-1) is a key regulator of cellular response to hypoxia and has been suggested as playing an important role in the regulation of tumor cell proliferation, survival, migration, and metastasis.