CTLA4 and systemic sclerosis: Therefore, as described for the first time in the present study, the higher efficacy exerted at the gene expression level by CTLA4-Ig in cultured circulating fibrocytes versus cultured skin fibroblasts/myofibroblasts isolated from the same SSc patients may represent a new approach for early intervention, acting on progenitor cells before their final homing and differentiation into active myofibroblasts.