TNF and chronic obstructive pulmonary disease: For instance, elevated levels of TNFα, and phosphorylation levels of p38 MAPK and ERK1/2, have been observed in COPD patients, and the inhibitors of p38 MAPK and TNFα have been shown to exhibit inhibitory effects on the inflammatory responses of COPD (Lemire et al., 2012; Zhang et al., 2019).