Interleukin 2 (IL-2) is a pleiotropic cytokine produced primarily by mitogen- or antigen-activated T lymphocytes. Human IL-2 (also known as T-cell growth factor) is produced by T-cells in response to antigenic or mitogenic stimulation. IL-2 is a potent lymphoid cell growth factor which exerts its biological activity primarily on T cells promoting proliferation and maturation.IL-2 has been found to stimulate growth and differentiation of B cells, NK cells, LAK cells, monocytes, and oligodendo