IL6 and chronic obstructive pulmonary disease: Increased levels of inflammatory markers have been demonstrated in patients with COPD and asthma, such as interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), IL-1β, C-reactive protein (CRP) [11, 12], as well as adipocytokines such as visfatin, apelin, adipolin, and FABP4 [13, 14].