B2M is a part of the MHC class I family that participates in the presentation of peptide antigens to the immune system. B2M is localized on the surface of numerous cells and abundant on the surface of white blood cells. High production or destruction of these cells causes B2M levels in the blood to raise. This increase is observed in people with cancers involving white blood cells， but it is mainly significant in people newly diagnosed with multiple myeloma. B2M Testing is done primarily when evaluating a person for certain kinds of cancer affecting white blood cells including chronic lymphocytic leukemia， non-Hodgkin’’s lymphoma， and multiple myeloma or kidney disease.
