TNF and systemic inflammatory response syndrome: In the early phase following injury, the response is regulated by acute phase reactants, proinflammatory mediators (TNF-α, IL-1, -6, -8, -18), and the activation of endothelial cells (expression of P- and E-selectins, ICAM-1, VCAM-1), leading to a so-called “sterile” systemic inflammatory response or SIRS.