Description: The CRM17 antibody reacts with human interleukin-1 receptor antagonist (IL-1RA). IL-1RA is produced by macrophages, monocytes, neutrophils, synovial and dermal fibroblasts. The 17 kDa soluble form of IL-1RA (sIL-1RA) is produced by hepatocytes. IL-1RA inhibits the release of both forms of IL-1, the secretion of IL-2, and the expression of IL-2 receptors on the cell surface. IL-1RA also blocks the stimulation of prostaglandin E2 synthesis in synovial cells and the proliferation of thymocytes.