Figure 1
From: Anti-cytokine therapy in chronic destructive arthritis

Simplified view of potential pathways of TNF overproduction. Deranged synoviocyte-mediated TNF production might initiate a TNF–IL-1 cascade. Note that general triggering of T cells or macrophages, as studied in arthritis models, gives rise to both TNF and IL-1, with considerable TNF-independent IL-1 production, and skewing to IL-1 when immune complexes are used as the stimulus.