The iLite® IL-2 Assay Ready Cells can be used for the quantification of IL-2 activity, or neutralizing antibody response against IL-2 in test samples, including human serum. IL-2 is an interleukin and part of the bodys natural response to microbial infection and a tool in the immune system discrimination between foreign ("non-self") and "self". It signals through the IL-2 receptor, a complex consisting of three chains, termed alpha, beta, and gamma. IL-2 has essential roles in key functions of the immune system, tolerance and immunity, primarily as a stimulant of T- and B-cell growth and maturation. IL-2 activates and stimulates the growth of immune cells, most importantly T-Cells, but also Natural Killer Cells (NK Cells), both can clear cancer cells directly. Anti-tumour effects of IL-2 appear to be mediated by its effects on NK Cells, Lymphokine-activated Killer Cells and other cytotoxic cells.