Clone D7715A7 recognizes the mouse CD126 antigen, a type I cytokine receptor also known as interleukin 6 receptor subunit alpha (IL-6Rα) or membrane glycoprotein 80 (gp80). CD126 is expressed on activated T and B cells, monocytes, hepatocytes, and plasma cells. It associates with the IL-6 receptor β chain (CD130 or gp130) resulting in the formation of a functional high affinity IL-6 receptor complex. IL-6 plays essential roles in immune response, acute phase reaction, and hematopoiesis. It is an essential factor for B cell differentiation to antibody-forming cells. Deregulated expression of the IL-6 gene is involved in polyclonal plasma cell abnormalities and oncogenesis of plasma cell neoplasias. IL-6 functions as a potent growth factor for multiple myelomas, as well as plasmacytomas. Clone D7715A7 blocks IL-6/IL-6 receptor interactions.