IL17A and systemic sclerosis: Nevertheless, even if there are many evidences of increased Th17 cell and IL-17A levels in peripheral blood, skin and lung in SSc, and it has been shown that SSc fibroblasts express high amount of IL-17 receptors 30, contrasting results about the effect of IL-17A on pro-fibrotic cytokines in SSc are available, with several data from human studies and experimental studies that argue toward an anti-fibrotic role of IL-17A 31.