Description: Mouse IL-1β, also called lymphocyte activating factor (LAF), endogenous pyrogen (EP), leucocyte endogenous mediator (LEM), mononuclear cell factor (MCF), is a ~17 kDa factor produced by a wide variety of cells, including macrophages, dendritic cells, T and B cells. IL-1β is mostly cell associated with 23% amino acid homology with IL-1α. The immune regulatory role of IL-1β is exerted on a wide range of cells including lymphocytes, epithelial cells and fibroblasts. In vivo, it induces hypotension, fever, and acute phase response.