HIF1A and chronic obstructive pulmonary disease: An increased risk of developing lung cancer was observed in smokers with airflow obstructions, particularly of squamous histological subtype in patients diagnosed with non-small cell lung carcinoma, compared to smokers with normal lung functions [33,34,35], and it has been shown a prognostic effect of hypoxia (measured through expression of HIF-1α) with COPD and lung cancer [36].