Recombinant Equine IL-1 Receptor AntagonistThe IL-1 family of cytokines encompasses eleven proteins that each share a similar barrel structure and bind to Ig-like receptors. Several of the well characterized members of the IL-1-like cytokines play key roles in the development and regulation of inflammation. In contrast, IL-1 receptor antagonist (IL-1ra; IL-1F3) and IL-36 receptor antagonist (IL-36ra; IL-1F5) reduce inflammation by blocking the binding of the agonist receptor ligands. IL-33 (IL-1F11) is thought to function as an 'alarmin' released following cell necrosis to alerting the immune system to tissue damage or stress. The biological properties of IL-37 (IL-1F7) are mainly those of down-regulating inflammation.