This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
[{'content': 'All of the following proteins are involved in the metabolism of iron, EXCEPT \nSelect and explain. \nA. Transthyretin, B. Ceruloplasmin, C. Ferritin, D. Hepcidin', 'role': 'user'}, {'content': "Answer: A \nExplanation: Transthyretin (formerly known as prealbumin) binds to T4 and forms a complex with retinol-binding protein. It is not involved in iron metabolism. Don't confuse it with Transferrin Ceruloplasmin is a copper containing ferroxidase oxidises any ferrous iron to ferric iron and Aceruloplasminemia leads to hemochromatosis Hepcidin is the main regulator of systemic iron homeostasis Ferritin-is an iron containing protein", 'role': 'assistant'}]