TNF and pulmonary fibrosis: TNF-α was one of the earliest cytokines implicated in the pathogenesis of lung fibrosis disease and, together with IL-1, has been found to over-express in regenerating type II pneumocytes in human lung, thus enhancing fibroblast proliferation [16].TNF-α genetic polymorphisms have been found significantly associated with increased risk of developing pulmonary fibrosis [17, 18].