IL2, also known as Interleukin2, is an immunoregulatory lymphokine produced by T-cell in response to antigenic or mitogenic stimulation IL2/IL-2R signaling is required for T-cell proliferation and other fundamental functions which are essential for the immune response. IL2 stimulates growth and differentiation of B-cells, NK cells, lymphokine activated kill cells, monocytres, macrophages and oligodendrocytes. Recombinant canine IL2 protein was expressed in E.coli and purified by using conventional chromatography techniques.