During fetal development, the developing embryonic tissues produce specific proteins that support the organism's function, growth, and development. These proteins are later replaced by proteins that play specific structural or transport roles throughout the organism's or individual's adult life.
Occasionally, tumor cells develop that begin producing these proteins associated with fetal development, called oncofetal antigens. The most widely studied oncofetal antigens are:
- Alpha-fetoprotein (AFP)
- Carcinoembryonic antigen (CEA)
