In regard to Smad pathway activation, TGF-β induced a rapid and sustained phosphorylation of Smad3 molecules in T lymphocytes from patients with SSc that was more intense than observed in T lymphocytes from healthy donors and in Jurkat T cells, although with no significant difference when we considered the nine patients with SSc (Fig. 3b). This evidence concerns the gene SMAD3 and systemic sclerosis.