Interleukin 1 receptor antagonist (IL1RN), also known as IL1-RA, is a member of the interleukin 1 cytokine family. IL1RN may represent a reservoir of IL-1 inhibitors, released upon cell death, whose function is no limit the pro-inflammatory signals but most prominently by mononuclear phagocytes and keratinocytes. IL1RN is reported to be associated with increased risk of osteoporotic fractures and gastric cancer.