IL6 and chronic obstructive pulmonary disease: Some serum biomarkers like interleukin-6 (IL-6), interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) have been found to be associated with airway inflammation in obstructive lung diseases, including COPD [4], asthma and bronchiectasis [5, 6].