RAG2 and synovial sarcoma: In order to evaluate the function of CCR7−/− Treg cells in vivo, we transferred Treg cells from CCR7−/− and WT mice into mice that exhibited inflammatory lesions in lacrimal and salivary glands resembling SS by the transfer of CCR7−/− CD25−CD4+ LN T cells into Rag2−/− mice (Fig. 4A and B).