Interleukin-1 Receptor Antagonist Protein (IL-1F3, IL-1ra) belongs to the IL-1 family of cytokines, whose members play key roles in the development and regulation of inflammation. IL-1 receptor antagonist (IL-1ra; IL-1F3) reduces inflammation by blocking the binding of the agonist receptor ligands. Chicken IL-1 Receptor Antagonist Recombinant Protein is purified interleukin-1 receptor antagonist protein (IL-1F3, IL-1ra) produced in yeast.