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
[{'content': 'CD4 is marker of \nSelect and explain. \nA. Monocyte, B. Tcell, C. Bcell, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref Robbins 7/e p670;9/e p191 There are 4 main types of T cells. CD4+ Helper Cells. CD4+ helper cells help in the maturation of B cells into plasma cells and memory B cells. ... CD8+ Cytotoxic Cells. CD8+ cytotoxic cells cause lysis of virus-infected and tumour cells. ... Memory T Cells. ... Natural Killer T Cells.', 'role': 'assistant'}]