TNF and Behcet disease: Emmi G. et al. [29] reported that T cells at the intestinal mucosal level produce a large concentration of TNF-α, and in the early stage of BD, Th1 and Th17 cells induce inflammation leading to mucosal damage though abnormal and long-lasting cytokine production as well as though both perforin- and Fas-Fas ligand-medicated cytotoxicity.