Abstract
This article summarizes studies in which the author has been involved over several decades, directed toward providing solutions for the three major limitations to the field of transplantation: (1) drug treatment-related complications; (2) chronic rejection; and (3) the availability of transplantable organs. The first two of these limitations may be overcome by induction of transplantation tolerance, while the third will also require a new source of organs, for which great strides are now being made in xenotransplantation through genetic engineering.