TNF and chronic obstructive pulmonary disease: Inflammation in COPD is typically driven by T-helper (Th) 1 immune responses, which enhance cell-mediated immunity and phagocyte-dependent inflammation through the production of interleukin (IL)-2, IL6, IL-8, IL-9, IL-17A, interferon-γ, and tumor necrosis factor (TNF)-α [15,16].