INTRODUCTION
Xenotransplantation procedures involving both whole organs and tissues will probably be developed
to a level of clinical relevance within the next decade (Alisky, 2004; Dorling, 2002; Hoerbelt and
Madsen, 2004; Ye et al., 1994). Transgenic technologies will continue to be involved in the
development of organs that would be resistant to host rejection phenomena. Most likely, a combined
strategy of transgenic manipulation and improvement of immunosuppressive agents and techniques
will be required to achieve success. Xenografic tissue implants, such as islet cells for diabetic
patients, are likely to be developed prior to whole-organ transplantation of such organs as the heart,
liver, and kidneys. Swine are generally considered to be the most likely species to be utilized in
clinical xenografic procedures. Primates are likely to be utilized only during initial experimental
procedures because of supply, public health, and ethical considerations.