Which of the following is a hormonal marker for germ cell tumors?

The correct answer is that Alpha-fetoprotein (AFP) is indeed a hormonal marker for germ cell tumors, particularly non-seminomatous germ cell tumors such as yolk sac tumors. AFP is a glycoprotein that is typically produced by the fetal liver and yolk sac during pregnancy. In adults, elevated levels of AFP can be indicative of certain tumors, especially those arising from germ cells.

In the context of germ cell tumors, AFP is most notably associated with tumors that can produce this protein, which include yolk sac tumors. Germ cell tumors can be classified into seminomas and non-seminomas, and while seminomas do not usually secrete AFP, the non-seminomatous types often do, making AFP a useful tumor marker for diagnosis and monitoring treatment response.

Beta-hCG can also be elevated in certain cases of germ cell tumors, particularly choriocarcinoma, which makes it another relevant marker in this context. However, the emphasis on AFP in germ cell tumors stems from its direct association with specific non-seminomatous types. Actin and CEA are not specific markers for germ cell tumors; actin is a component of muscle cells, and carcinoembryonic antigen (CEA) is typically