Nailing down the language of stem cell biology

Two words that rarely pass the lips of Irving L. Weissman, M.D., in public are “embryo” and “clone.” He has reason for caution. In January, when Stanford University announced that Weissman would lead a privately funded stem cell research project, some press accounts gave the false impression that his research was directed toward reproductive cloning. As the first scientist to isolate hematopoietic stem cells, Weissman has a long history in the field and believes that both the public and many researchers misuse the terminology. “Those [are] two terms we ought to have an understanding about,” he said at a talk at the medical school in January. “Otherwise we can’t discuss this issue.”

Like most of the scientific community, Weissman is adamantly opposed to reproductive human cloning. He is concerned, however, that the government will ban what is commonly known as “therapeutic cloning,” or the use of nuclear transfer techniques to seek treatments for disease. “If you are in a position of authority to enact a ban on this kind of research, you are responsible for the potential lives that are lost,” he said.