This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
All are B-cell marker except: 
Select and explain. 
A. CD15, B. CD19, C. CD21, D. CD24
A: CD15
Answer: A: CD15 
Explanation: Direct lines from Wintrobes hematology..CD-15 is expressed on neutrophils, esinophils and monocytes but not on on platelets,lymphocytes and erythrocytes.About option (d)CD24 is expressed on B cell activation and differentiation and is lost at the plasma cell stage. It is also present ion granulocytes and thymocytes but not on mature T cells.data shows its increased levels are associated with colon/breast and pancreatic cancer.( ref Robbins 7th/670,9/e590)