Question: what is a beta 2 microglobulin test?
Answer: What is a beta-2 microglobulin tumor marker test? This test measures the amount of a protein called beta-2 microglobulin (B2M) in the blood, urine, or cerebrospinal fluid (CSF). B2M is a type of tumor marker. Tumor markers are substances made by cancer cells or by normal cells in response to cancer in the body.