Alpha-fetoprotein (AFP) is a protein produced primarily by the liver in a developing baby (fetus) and the portion of a developing embryo that is similar to the yolk cavity in bird eggs (yolk sac tissues). AFP levels are typically elevated when a baby is born and then decline rapidly. Liver damage and certain cancers can increase AFP concentrations significantly. This test measures the level of AFP in the blood.AFP is produced whenever liver cells are regenerating. With chronic liver diseases, such as hepatitis and cirrhosis, AFP may be chronically elevated. Very high concentrations of AFP may be produced by certain tumors. This characteristic makes the AFP test useful as a tumor marker. Increased amounts of AFP are found in many people with hepatocellular carcinoma. They are also found in some people with cancers of the testicles or ovaries.