Purity > 90% as determined by SDS-PAGE. MW: 45kDa. Full Length of Mature Protein: 113-271aa. N-terminal GST-tagged. Homo sapiens (Human). Produced by activated macrophages, IL-1 stimulates thymocyte proliferation by inducing IL-2 release, B-cell maturation and proliferation, and fibroblast growth factor activity. IL-1 proteins are involved in the inflammatory response, being identified as endogenous pyrogens, and are reported to stimulate the release of prostaglandin and collagenase from synovial cells.