TNF and systemic sclerosis: In further studies, it would be interesting to evaluate the possible influence of immunosuppressive agents (i.e., methotrexate, mycophenolate mofetil, TNF-a inhibitors, or rituximab) and corticosteroids at an equivalent dose of prednisone ≥ 10 mg/day on the peripheral blood CD21low B cells and on the DAS28-ESR assessment, since, in this study, we excluded SSc patients that received these treatments in the last 6 months.