Xenotransplantation of cells and tissues: application to a range of diseases, from diabetes to Alzheimer's.

The ability to cross species lines will dramatically expand the number of patients and the scope of human diseases that can be treated successfully with transplantation. In addition to whole organs, the transplantation of cells and tissues with specific differentiated functions represents an important conceptual and medical advance. In the USA alone, over 15 million patients suffer from diabetes, over 7 million patients suffer from neurodegenerative diseases, and millions more suffer from liver failure, AIDS, hemophilia and other disorders caused by tissue loss or dysfunction. Clinical trials using animal cells to treat many of these diseases are already under way, and it seems likely that this list will continue to grow as researchers identify new bioactive molecules and expand their understanding of the role different cells play in the human disease process.