IL13 and systemic sclerosis: It has recently been demonstrated that methylation of STAT6 determines its phosphorylation and modulates its DNA binding activity in response to exogenous stimulation28, thus adding another layer of complex regulation Because IL-13 shares its signalling with the shared co receptor IL-4α we measured the levels of this, we could find no increase in IL-4α in SSc fibroblasts compared to controls and this could not be modulated by oxidative stress either, as ROS is important in fibrogenesis.