This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Medicine
[{'content': 'Cystatin C is used for ? \nSelect and explain. \nA. Diagnosis of acute renal failure, B. Transplant survival, C. Sepsis, D. Pancreatitis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Refer to question no 242(explanation is given there ) Cystatin C or cystatin 3, a protein encoded by the CST3 gene, is mainly used as a biomarker of kidney function. Recently, it has been studied for its role in predicting new-onset or deteriorating cardiovascular disease. It also seems to play a role in brain disorders involving amyloid, such as Alzheimer's disease. Ref Harrison20th edition pg 287", 'role': 'assistant'}]