TNF and idiopathic pulmonary fibrosis: In the initial stage of IPF, a variety of proinflammatory factors (such as TNF-α, IL-6, IL-1, and TGF-β) and matrix metalloenzymes secreted by fibroblasts participate in the chemotaxis and proliferation of inflammatory cells and the mediation of intercellular interaction, promoting the further progress of inflammatory repair reaction [28].