IL-6 is a family of cytokines that have been associated with lung injury and the initiation of lung fibrosis,159 with fewer fibrotic changes seen in IL-6 deficient mice.160,161 Animal models show that this cytokine increases the expression of TGF-β receptors and their signal transduction,162 demonstrating another link between inflammation and fibrosis. Here, IL6 is linked to pulmonary fibrosis.