<s>[INST] HI my mom is suffering from multiple myeloma and undergoing treatment for the same.I just wanna ask about the importance of serum beta 2 microglobulin test and its importance in the disease mentioned above b coz inspite of others tests being normal ,this test always shows a higher value.please answer .I will be thankful to you. [/INST] Hi and thanks for the question. Beta 2 microglobuilin is a small protein associated with multiple myeloma. In course of this disease, some chains of particular antibodies, including Beta 2 micrglobulin are produced. The quantity or concentration of this substance in blood gives an indication of the stage of the disease, and measures the outcome or prognosis. The lower the concentrations of this substance, the better the outcome. It is therefore measured to know the stage of the disease and to monitor the evolution of the patient under treatment. Increasing values imply that the treatment is not very effective, whereas decreasing values implies the effectiveness, and good prognosis of the patient. It is actually a measure of the morbidity and the mortality of the disease. Thanks and hope this helps, Luchuo, MD. </s>