The human IL-2 protein, also known as interleukin-2, is an important cytokine that plays a vital role in regulating the immune system. It is produced by activated T cells and stimulates the proliferation and activation of various immune cells, such as T cells, B cells, and natural killer cells. IL-2 also promotes the development of immune memory and enhances the effectiveness of the immune response against infections and cancers. In addition, IL-2 has been used therapeutically in the treatment of certain diseases, such as cancer and autoimmune disorders, to boost the immune system.