IL6 and chronic obstructive pulmonary disease: Irrespective of the source, elevated circulating levels of inflammatory biomarkers, such as tumor necrosis factor-alpha (TNFα), C-reactive protein (CRP), interleukin (IL)-6, and IL-1β have all been associated with severity and exacerbations of COPD and may contribute to comorbidities accompanying COPD [9-11].