TNF and chronic obstructive pulmonary disease: DRSA is associated with chronic obstructive pulmonary disease (COPD)32, the production of inflammatory cytokines, including tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β)33, as well as the inflammatory marker proteins nitric oxide (NO)34 and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α)35.