High numbers of infiltrating activated macrophages and T cells have been detected in skin of patients with SSc [36,37] and these cells are key producers of a variety of pro-fibrotic cytokines such as transforming growth factor-beta (TGF-β), CC-chemokine ligand 2, and IL-4 and IL-17 [38-40]. Here, IL17A is linked to systemic sclerosis.