IL4 and systemic sclerosis: Inflammatory cytokines including interleukin-4 (IL-4), IL-13, transforming growth factor-β (TGF-β), and oncostatin-M have all been linked to the development of fibrosis in autoimmune conditions such as systemic sclerosis or interstitial lung disease (Mozaffarian et al., 2008, Roberts et al., 1986, Sempowski et al., 1994, Zhu et al., 1999).