Prospects in xenotransplantation: a personal view.

There are 3 major obstacles to performing transplantations from pig to human. They are as follows: a powerful immune barrier, a potential risk for transmitting microorganisms, particularly endogenous retrovirus from animal-to-human, and ethical issues related to patients and society at large. However, steady progress is currently being made in overcoming these obstacles. Once pig organs can be transplanted into humans, there will be unlimited access to undamaged organs and cells for transplantation, and surgeons will be able to offer transplantations to all needy patients without undue delay. Donation from deceased or live human beings will become obsolete. Furthermore, it will be possible to alleviate graft rejection by genetic modification of the source animal.