<prompt> Beta-2 microglobulin is used as a tumor marker for which of the following diseases?Multiple myelomaAcute lymphoblastic leukemiaHairy cell leukemiaLymphoplasmacytic lymphoma  <response>: Tumor marker for multiple myeloma is Serum beta-2 microglobulin Serum beta-2 microglobulin level 3.5mgL indicates better prognosis 