This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Non Hodgkin Iymphoma, Subject name: Pathology
Mantle cell lymphomas are positive for all of the following, except: 
Select and explain. 
A. CD 23, B. CD 20, C. CD 5, D. CD 43
A: CD 23
Answer: A: CD 23 
Explanation: Mantle cells lymphomas are usually CD23 negative. They are positive for CD5, CD20 and CD43.