Fetoprotein, or alpha-fetoprotein (AFP), is a protein produced by the liver of a developing fetus. It plays a crucial role in fetal development, helping to transport nutrients and protect the fetus from the mother's immune system. AFP levels are typically high during pregnancy and gradually decrease after birth. In adults, elevated levels of alpha-fetoprotein can indicate certain medical conditions, such as liver disease or specific types of cancer, including hepatocellular carcinoma. Therefore, measuring AFP levels can be an important diagnostic tool for healthcare providers in monitoring and diagnosing these conditions.