IL10 and synovial sarcoma: Since, unlike what was observed in controls, the Breg of SS samples seem unable to release IL10 in the presence of CpS-hUCMS we might assume that the Breg of SS patients are characterized by functional defects (38), and that they need the joint stimuli of CpS-hUCMS, CD3s and the Tc in order for them to release the IL10 stored in the cytoplasm.