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. IL1RA Human Recombinant produced in E.Coli is a non-glycosylated, N-terminal methionyl form of the human naturally-occurring polypeptide chain containing 153 amino acids and having a molecular mass of 17000 Dalton.