Beta-2-microglobulin review: its relevance in clinical oncology.

Beta-2-microglobulin (beta 2-m) is an intrinsic part of the HLA system and is most probably involved in cell recognition. The levels of free beta 2-m in the blood and urine are influenced by beta 2-m production and its clearance and destruction in the kidney. Many tumors can be associated with an elevated serum beta 2-m, the reason is unknown. The most promising application of beta 2-m as a tumor marker would appear to be lymphoid malignancies, especially multiple myeloma and chronic lymphocytic leukemia.