TNF and chronic obstructive pulmonary disease: Whereas, in COPD the cumulative effects of cigarette smoke and other chemical irritants result in a pro-inflammatory cell-mediated immune response facilitated by cytokines such as IL-1 beta, IL-6, tumor necrosis factor (TNF) alpha and a variety of T helper 1 (Th1) related chemotactic factors (Barnes 2016, 2009; Schuijs et al. 2013; Barnes 2017).