IL6 and chronic obstructive pulmonary disease: Additionally, systemic inflammatory markers and cytokines such as interleukin-6 (IL-6), IL-8, fibrinogen, α1-antitrypsin, myeloperoxidase, C-reactive protein (CRP), and tumor necrosis factor alpha (TNF-α) are high with COPD in the exacerbation phase [3,4].