Particularly there are few data concerning the pathogenic relationship between IL-17 and CTGF; accordingly with our results, it has been reported that IL-17A significantly decreases the mRNA expression of CTGF and α(Ι) collagen in scleroderma fibroblasts 6; conversely IL-17A addition in fibroblast cultures obtained from an animal model of bleomycin-induced fibrosis, increases the expression of CTGF and increases skin fibrosis 9. This evidence concerns the gene CCN2 and fibrosis.