These observations are congruent, at least in part, with increased expression of IRF5, TLR4, and critical endogenous TLR4 ligands found in murine model of systemic sclerosis, providing evidence that IRF5, after activation by TLR4, binds to the promoters of several key genes involved in the pathogenesis of systemic sclerosis [62]. This evidence concerns the gene IRF5 and systemic sclerosis.