Description: Inhibits the activity of IL-1 by binding to its receptor. Has no IL-1 like activity. (www.uniprot.org) Mouse recombinant IL-1 ra produced in E.coli is a single, non-glycosylated, polypeptide chain containing 153 amino acids and having a molecular mass of 17.4kDa. Interleukin-1 ra is a member of the interleukin 1 cytokine family. This protein inhibits the activities of interleukin-1 alpha (IL1A) and interleukin-1 beta (IL1B), and modulates a variety of interleukin-1 related immune and inflammatory responses. This gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2. A polymorphism of this gene is reported to be associated with increased risk of osteoporotic fractures and gastric cancer. Four alternatively spliced transcript variants encoding distinct isoforms have been reported.