CALR and synovial sarcoma: Specifically, ELS allow the selection and differentiation of autoreactive B cells into high-affinity plasma cells reacting against citrullinated antigens in RA (49), anti-ribonucleoproteins Ro/SSA and La/SSB in SS (40), thyroglobulin and thyroperoxidase in Hashimoto’s thyroiditis (35), and insulin in type 1 diabetes (51, 52).