When tumour cells are exposed to hypoxia, hypoxia-inducible factor-1 (HIF-1), which is a transcription factor composed of HIF-1α and HIF-1β subunits (Wang et al, 1995; Wang and Semenza, 1996), is activated and then it promotes the transcription of several genes such as glucose transporters, glycolytic enzymes, and angiogenic factors (Dang and Semenza, 1999). The gene discussed is HIF1A; the disease is neoplasm.