IL1A and Fever: Fever in humans is generally initiatedby the production of proinflammatory cytokines, such as TNF-α,IL-1, and IL-6, by immune cells in response to exogenous pyrogens.These cytokines, particularly IL-1 and IL-6, bind to their respectivereceptors on brain endothelial cells, where they induce the expressionof cyclooxygenase-2 (COX-2), ultimately leading to the productionof prostaglandin E2, a final mediator of fever.