Interleukin-1 (IL-1) is an extracellular peptide of 17 kDa that designates two proteins, IL-1α and IL-1β.  In general, Interleukin 1 is responsible for the production of inflammation, as well as the promotion of fever and sepsis.IL-1α inhibitors are being developed to interrupt those processes and treat diseases.IL-1α is produced mainly by activated macrophages, as well asneutrophils, epithelial cells, and endothelial cells. It possesses metabolic, physiological, haematopoietic activities, and plays one of the central roles in the regulation of the immune responses. It binds to the interleukin-1 receptor. It is on the pathway that activates tumor necrosis factor-alpha.
IL-1α has been administered to patients during receiving autologous bone marrow transplantation. There is currently a head and neck phase III trial being run by Cel-Sci Corp. involving IL-1αand many other interleukins (Multikine) as an immunotherapy. In dermatology and cosmetics topical IL-1α has been shown to increase the production of collagen and other components of the dermal matrix.