These differences are in line with decreased IL-10 secretion by B cells stimulated with PMA/ionomycin, and a reduced frequency of IL-10-producing transitional B cells, either stimulated with PMA/ionomycin alone or pre-activated with an anti-BCR antibody and CpG, observed in patients with SSc (Fig. 3b-c). This evidence concerns the gene IL10 and systemic sclerosis.