IL-2Rβ, or Interleukin-2 Receptor Beta, 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-2Rβ is primarily expressed on the surface of activated T cells and is important for their proliferation and survival. The IL-2 receptor complex consists of three subunits: IL-2Rα, IL-2Rβ, and IL-2Rγ. The interaction of IL-2 with these subunits leads to signaling pathways that promote T cell activation and differentiation. Dysregulation of IL-2Rβ can contribute to various immune disorders, including autoimmune diseases and cancer.