Protraction of this process then results in chronic lung inflammation as well as lung fibrosis as pro-inflammatory cytokines such as IL-1, IL-18, and TNFα enhance the recruitment and proliferation of fibroblasts and mesenchymal cells to produce fibroblastic foci and to generate components of the extracellular matrix including collagen, leading to fibrotic scarring of the lung tissue [180]. This evidence concerns the gene TNF and pulmonary fibrosis.