IL17A and systemic sclerosis: Th17 cells are involved in the pathogenesis of several rheumatic autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, Sjogren syndrome, psoriatic arthritis 4; their role in the pathogenesis of SSc has recently emerged 5 as it has been reported that IL-17, which is the main cytokine secreted by Th17 cells, is overproduced by T cells from the peripheral blood and in fibrotic lesions of the skin and lungs in SSc patients and it is able to enhance the proliferation of fibroblasts in vitro6.