Interleukin-2 (IL-2) is a cytokine signaling molecule that regulates white blood cells. It is produced primarily by T cells after activation by an antigen. IL-2 signals through the IL-2 receptor which leads to the activation of at least 2 major signaling pathways which mediate cell growth, survival, activation induced cell death and differentiation. A pro-inflammatory cytokine, IL-2 activates T cells to produce TNFα as well as IFNγ and controls immune response by contributing to the development of regulatory T cells. Therefore IL-2 plays an important role in antigen specific immune responses