TNF and rheumatoid arthritis: In the in vitro culture system, EGCG does not directly cause cytotoxicity of RA synovial fibroblasts, but promotes apoptosis in TNF sensitized cells by blocking myeloid cell leukemia 1 expression (82); inhibits IL-1β induced chemokine production and MMP2 activation (83); and inhibits IL-6 synthesis and suppresses IL-6 trans-signaling by inducing production of soluble gp130 production (80).