Acute-phase proteins are a class of proteins whose plasma concentrations increase (positive acute-phase proteins) or decrease (negative acute-phase proteins) in response to inflammation. This response is called the acute-phase reaction (also called acute-phase response). In response to injury, local inflammatory cells (neutrophil granulocytes and macrophages) secrete a number of cytokines into the bloodstream, most notable of which are the interleukins IL1, IL6 and IL8, and TNFa. The liver responds by producing a large number of acute-phase reactants. At the same time, the production of a number of other proteins is reduced; these are, therefore, referred to as "negative" acute-phase reactants. Increased acute phase proteins from the liver may also contribute to the promotion of sepsis.