IL10 and synovial sarcoma: Although IL10 is considered proinflammatory in SS [42, 43] likely by promoting survival, proliferation, and antibody production of B cells [44], it generally inhibits the maturation and function of APCs and also directly suppresses the differentiation of proinflammatory Th1 and Th17 subsets [45]; hence, its pathogenic effects on SS likely depend on the stage of disease and cell types producing IL10 as indicated by researches in other autoimmune diseases [46, 47].