Xenotransplantation has become a miracle word, nowadays to be heard quite often among transplant professionals, but also outside the scientific and medical community. The reason for this great interest and the particular fascination about the idea is the almost desperate hope to solve the present organ shortage and to expand transplantation into an unlimited space in order to make it available for every sick patient in need. The idea behind xenotransplantation dates back to 1667, when the French doctor Jean-Baptiste Denys tapped the veins of farm animals to perform human blood transfusions. Apart from the clinical demand, however, there are evolutionary obstacles to overcome which include immunological and other biological differences between species. Also, ethical considerations about the benefits and risks play a key role in the present discussions.
