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: Medicine
[{'content': 'Nissl substance is found in: March 2013 \nSelect and explain. \nA. Neuron, B. Hepatocytes, C. Cardiocytes, D. ENterocytes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A i.e. Neuron Nissl body/Nissl or tigroid substance It is a large granular body found in neurons. These granules are rough endoplasmic reticulum (RER) with rosettes of free ribosomes, and are the site of protein synthesis. It was named after Franz Nissl, a German neurologist who invented the Nissl staining method', 'role': 'assistant'}]