IL-2Rα, or Interleukin-2 receptor alpha, is a protein that plays a crucial role in the immune system. It is part of the receptor complex for Interleukin-2 (IL-2), a cytokine that helps regulate the growth and activity of T cells, which are essential for immune responses. IL-2Rα is primarily expressed on activated T cells and is important for their proliferation and survival. The IL-2 receptor consists of three subunits: IL-2Rα, IL-2Rβ, and IL-2Rγ. When IL-2 binds to this receptor complex, it triggers signaling pathways that enhance T cell function. This process is vital for maintaining immune homeostasis and responding effectively to infections and diseases, including cancer.