This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Which of he following is not a cyclin dependent kinase (CDK) inhibitor? \nSelect and explain. \nA. p21, B. p27, C. p53, D. P57', 'role': 'user'}, {'content': 'Answer: C \nExplanation: . p53', 'role': 'assistant'}]