We also identified another protein, PBP, possibly important in the development of fibrosis in SSc patients, based on the observation that PBP regulates human fibroblast growth by activation of platelet-derived growth factor receptor [31]–[33], whereas its derivate, the connective tissue-activating peptide-III (CTAP-III), stimulates the glycosaminoglycan formation, participating in the extracellular matrix remodelling. Here, PPBP is linked to systemic sclerosis.