Like all Americans, I believe our nation must vigorously pursue the tremendous possibility that science offers to cure disease and improve the lives of millions. We have opportunities to discover cures and treatments that were unthinkable generations ago. Some scientists believe that one source of these cures might be embryonic stem cell research. Embryonic stem cells have the ability to grow into specialized adult tissues, and this may give them the potential to replace damaged or defective cells or body parts and treat a variety of diseases.