TNF and Arthritis: The supernatants from E2-treated animals showed reduced levels of IL-17 (-51%, P <0.01), IL-2 (-27%, P <0.05), interferon-gamma (IFN-γ) (-23%, P <0.05), and IL-6 (-28%, P <0.05) versus placebo treatment, whereas levels of IL-4, TNFα, and GM-CSF (granulocyte macrophage colony-stimulating factor) were unchanged (Table 1), demonstrating that E2 treatment results in an altered systemic cytokine profile which may be important in the amelioration of arthritis.