This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood, Subject name: Pathology
[{'content': 'Beta-2 microglobulin is a marker for? \nSelect and explain. \nA. Multiple Myeloma, B. Mycosis fungoides, C. B-Cell lymphoma, D. Mantle cell lymphoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Multiple myeloma * Serum b2 microglobulin is increased in multiple myeloma and is the most important prognostic factor and can substitute for staging.* b2 Microglobulin level:a) < .004g/L - Median survival of 43 months.b) .004 g/L - Median survival of only 12 months.", 'role': 'assistant'}]