It has been shown that hypoxia-inducible factor 1α (HIF1α) can be activated by the stimulation of hypoxia and also by the stimulation of nicotine in lung cancer [113], suggesting HIF1α is expressed by the stimulation of both hypoxia and xenobiotic toxicity nicotine in middle stage LSCC. The gene discussed is HIF1A; the disease is lung carcinoma.