Beta-2-microglobulin [MD24R]

β2-microglobulin (B2M) is a principal component of the Major Histocompatibility Complex (MHC) class I molecule, a ternary membrane protein complex that displays fragments derived from proteolyzed cytosolic proteins on the surface of cells for recognition by the surveillance immune system. As an integral component of the MHC class I complex, β2-microglobulin plays a critically important role in immune system function. It has important relevance to cancer biology research; for example, research studies have shown that nearly one third of diffuse large B cell lymphomas contain mutations that inactivate β2-microglobulin gene function, thereby allowing tumor cells to escape immune detection. In addition, β2-microglobulin has been identified as an amyloid preprotein with collagen-binding affinity (5); its accumulation in osteoarthritic lesions of long-term dialysis patients is reportedly a contributing factor to the condition known as amyloid osteoarthropathy.