The majority of patients in need of organ transplants do not survive long enough for a suitable human organ to become available. Xenotransplantation, the transplant of animal organs into humans, has attracted substantial media attention. If, as appears likely, it proves possible to "humanize" animal organs and evade the problems of rejection, in the coming few years there will be a tremendous increase in this procedure, mostly using organs from animals specifically for their harvestable organs. This book will lay out the potential and promise of the technique, the history of organ transplantation, the technical problems and breakthroughs in overcoming immune rejection, and typing and humanizing donor organs for transplantation. The ethical question of growing animals specifically for organ harvest, and the substantial public health concern from the certainty that animal viruses will pass into humans with the donated organs, will be fully discussed. The authors are among the leaders in the field of Xenotransplantation.