KDR and pulmonary emphysema: Vascular endothelial growth factor (VEGF) has been proposed to be an integral part of the homeostatic adult lung structure maintenance program [8] and the expression of the VEGF ligand and the VEGF receptor 2 (VEGFR2 (KDR)) proteins has been shown to be decreased in human lung tissue and airway samples from patients with severe COPD/emphysema [9], [10].