Wanted: Pig Transplants That Work
Jennifer Couzin
A shortage of human organs has spurred researchers to look for replacements from animals. Although whole-organ transplants into humans have been largely abandoned in industrialized nations due to massive immune rejection and other safety worries, researchers hope they may someday be practicable. Clinical trials of cell and tissue xenotransplants, meanwhile, are under way in Europe and the United States, where they are tightly regulated. Thus far, results have been mixed.