b2 microglobuli.is a  β-Globuline

Component of the HLA System. Present on the surface of lymphocytes and most nucleated cells. Filtered by renal glomeruli because of its small size but for the most part (more than 99%) is reabsorbed. 

We find high serum levels in renal failure. In some diseases we can have an overproduction. 

It can be used as a tumor marker for: 

• leukemia 
• lymphoma 
• multiple myeloma