The interleukin-2 receptor beta (IL2RB), also known as CD122. is a critical subunit of the IL-2 and IL-15 receptor complexes, playing a pivotal role in immune regulation. It is constitutively expressed on immune cells, including regulatory T cells (Tregs), natural killer (NK) cells, and memory CD8+ T cells. IL2RB pairs with the common gamma chain (γc, CD132) to form functional receptors that activate JAK-STAT signaling pathways, particularly JAK1/JAK3 and STAT5. driving cell proliferation, survival, and differentiation. Antibodies targeting IL2RB are valuable tools for studying receptor function, modulating immune responses, or developing therapeutics. Neutralizing anti-IL2RB antibodies can block IL-2/IL-15 signaling, suppressing effector T cell and NK cell activity, which may be leveraged in autoimmune diseases or graft-versus-host disease. Conversely, agonist antibodies might enhance receptor signaling to boost antitumor immunity. However, therapeutic applications require precise targeting due to IL2RB's dual role in promoting both pro-inflammatory and immunosuppressive pathways. Research-grade IL2RB antibodies are widely used in flow cytometry, immunohistochemistry, and functional assays to characterize immune cell subsets or dissect signaling mechanisms. Challenges remain in optimizing specificity and minimizing off-target effects, given structural similarities among cytokine receptors. Overall, IL2RB antibodies continue to advance both basic immunology research and translational drug development.