This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
NK cells have which CD marker ?- 
Select and explain. 
A. CD 3, B. CD 56, C. CD 19, D. CD 13
B: CD 56
Answer: B: CD 56 
Explanation: Harshmohan textbook of pathology 7th edition. *NK cells comprises about 10 to 60 % of circulating lymphocytes. These lymphocytes do not have B or T cell marker.NK cell carries surface molecule of CD2, CD16, CD56 but negative for T cell marker CD3