TNF and chronic obstructive pulmonary disease: Among them, MAPK8, MAPK3, and MAPK1 are intracellular serine/threonine protein kinases, which can change gene expression by phosphorylation of transcription factors, promote the production of inflammatory factors TNF-α, IL-1, IL-6, and induce a series of inflammatory and immune responses, thus playing a role in the pathogenesis of COPD (Kang et al., 2013; Duan et al., 2020).