VEGFA and chronic obstructive pulmonary disease: Elevated levels of soluble TNF receptor-1 (sTNFR-1), Osteoprotegerin and neutrophil gelatinase associated lipocalin (NGAL) were associated with GOLD stage and frequency of exacerbation in the Bergen COPD cohort [13], [14], and myeloperoxidase (MPO) and vascular endothelial growth factor (VEGF) were associated with the severity of lung function impairment and dyspnea in a separate study [15].