Interleukin-1β-Deficient Mice

There are three members of the interleukin-1 (IL-1) gene family: IL-1α, IL-1β, and IL-1 receptor antagonist (IL-1Ra). IL-1α and IL-1β are agonists and IL-1Ra is a specific receptor antagonist. IL-1α and IL-1β are synthesized as precursor molecules, without leader sequences. The molecular weight of each precursor is 31 kDa. Processing of IL-1α or IL-1β to “mature” forms of 17 kDa requires specific cellular proteases.