. In order to determine the contribution of lymphoid neogenesis in the disease course of Behçet's arthritis, we investigated the synovial fluid (SF) levels of CXCL 12, CXCL 13, CCL 21 homeostatic chemokines and the percentage of SF naive lymphocytes expressing their receptors such as CXCR4+ and CCR7+. We further measured the SF TGF-Beta and INF-Beta levels which are known to contribute lymphoid neogenesis via leading persistent expression of CXCR4 on T cells and inhibiting T cell apoptosis, respectively.