VEGFA and chronic obstructive pulmonary disease: The fact that VEGF upregulation positively correlates with the increased levels of inflammatory mediators in sputum not only in bronchitis type of COPD smokers but also in asymptomatic smokers, may indicate that VEGF plays an important signalling role linking the inflammatory milieu with changes in bronchial epithelium and endothelium quite early in smokers' airways.