TNF and infection: It took nearly a century to unravel the mysteriesof the immune system and the role of the immune system in cancer.3 In response to an inflammatory signal (secondary to infection or cancer), theantigen-presenting cells (APCs) responding to the antigen are stimulated by theproinflammatory cytokines [interleukin (IL)-1, tumor necrosis factor (TNF)-α] andthe APCs interact with naïve T cells.