IL-1α is predominantly a cell-associated, non-secreted proinflammatory cytokine. It is produced in a variety of cells including monocytes, tissue macrophages, keratinocytes and other epithelial cells. High levels of IL-1α are associated with sepsis, rheumatoid arthritis, inflammatory bowel disease, acute and chronic myelogenous leukemia, insulin-dependent diabetes mellitus, and atherosclerosis.