Interleukin-18 (IL-18), also known as interferon-gamma inducing factor, is a protein which in humans is encoded by the IL18 gene. The protein encoded by this gene is a proinflammatory cytokine. IL-18 is a cytokine that belongs to the IL-1 superfamily and is produced by macrophages and other cells.
After stimulation with IL-18, natural killer (NK) cells and certain T cells release another important cytokine called interferon-γ (IFN-γ) or type II interferon that plays an important role in activating the macrophages or other cells. IL-18 is also able to induce severe inflammatory reactions. IL-18 has also been found to increase the Alzheimer’s disease-associated amyloid-beta production in human neuron cells.