IL-1β is a member of the interleukin 1 family of cytokines. This cytokine is produced by activated macrophages, monocytes, and a subset of dendritic cells known as slanDC, as a proprotein, which is proteolytically processed to its active form by caspase 1 (CASP1/ICE). This cytokine is an important mediator of the inflammatory response, and is involved in a variety of cellular activities, including cell proliferation, differentiation, and apoptosis. The induction of cyclooxygenase-2 (PTGS2/COX2) by this cytokine in the central nervous system (CNS) is found to contribute to inflammatory pain hypersensitivity. IL-1β, in combination with IL-23, induced expression of IL-17, IL-21 and IL-22 by γδ T cells. Increased production of IL-1β causes a number of different autoinflammatory syndromes, most notably the monogenic conditions referred to as Cryopyrin-Associated Periodic Syndromes (CAPS). Intestinal dysbiosis has been observed to induce osteomyelitis through a IL-1β dependent manner.