TNF and chronic obstructive pulmonary disease: A meta-analysis of evidence on the anti-inflammatory impact of CHM in patients with COPD has shown that CHM treatment leads to reductions in serum levels of interleukin (IL)-6, IL-8, tumor necrosis factor alpha (TNF-α) and transforming growth factor beta 1 (TGF-β1), as well as decreases in sputum levels of IL-8 and TNF-α (Miao et al., 2016).