In 1984, a 12-day-old infant, Baby Fae, received a baboon’s heart. She lived for 20 days before her body rejected the transplanted heart. Since the supply of human organs is far less than the need for human organs, researchers continue to search for alternative sources of organs. In 1999, the Food and Drug Administration (FDA) prohibited the use of nonhuman primate organs for human transplantation unless researchers could assess the risk of disease. A major concern had been that viruses and other diseases that were harmful to the animals would be deadly to humans. Researchers continue to search for alternate sources of organs, including pigs.