ELANE and chronic obstructive pulmonary disease: The innate immune system response is stimulated in COPD patients coincides with the expression of cytokines such as interleukin-8 (IL-8), matrix metalloproteinase protein-9 (MMP-9), and neutrophil elastase (NE) in certain micro-anatomical regions of pulmonary parenchyma and intra-alveolar septum.