CXCL8 and chronic obstructive pulmonary disease: The expression of VEGF after 14 days of treatment with PlGF, TNF-α or IL-8 using concentrations close to those in the BAL fluid of patients with COPD (PlGF 50 pg/ml, TNF-α 200 pg/ml and IL-8 200 pg/ml) is shown in fig 3A.