TGFB1 and systemic sclerosis: To test the hypothesis that disease specific alterations of the differentiation competence of a common mesenchymal precursor cell may contribute to development and progression of both, vasculopathy and fibrosis in SSc, we studied long-term treatment (6 days) of H-MSCs and SSc-MSCs with the SSc microenvironment-defining GFs CTGF, b-FGF, PDGF-BB, and TGF-β1.