IL1RA 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.