Hypoxia activates and mediates the heterodimeric transcription factor termed hypoxia-inducible factor-1 (HIF-1).2 HIF-1 is composed of α and β subunits, and HIF-1α triggers the biological behavior of tumor cells under hypoxic conditions, including proliferation, invasion, metastasis, enhanced resistance to chemotherapy, recurrence, and poor clinical prognosis.3-5. The gene discussed is HIF1A; the disease is neoplasm.