Under conditions of lung injury, inflammation and the immune response promote the formation of IPF, and cytokines that are involved in this process, such as TGF-β, TNF-α, IL-1β and IL-6, cause inflammatory cells to infiltrate, differentiate and undergo maturation, and promote further secretion of inflammatory cytokines and inflammatory transmitters by these cells, thus resulting in alveolitis and further lung injury [38]. This evidence concerns the gene TNF and hypersensitivity pneumonitis.