TNF and arthritic joint disease: In addition, FABP4 activates JNK1 to enhance production of cytokines such as tumor necrosis factor α (TNF-α), interleukin 1β, and monocyte chemoattractant protein 1 (MCP-1), which in turn propagates inflammatory reactions in arthritis, atherosclerosis, non-insulin-dependent diabetes mellitus and tumor formation [6].