On Porcine Xenotransplants
From the perspective of 2008, it seems plausible that xenotransplantion could become economically competitive with stem-cell based tissue engineering of replacement organs for long enough to become widespread. Competition is good - it drives people to achieve more, faster. "Alternatives to the use of human organs for transplantation must be developed and these alternatives include stem cell therapy, artificial organs and organs from other species, i.e. xenografts. For practical reasons but most importantly because of its physiological similarity with humans, the pig is generally accepted as the species of choice for xenotransplantation. Nevertheless, before porcine organs can be used in human xenotransplantation, it is necessary to make a series of precise genetic modifications to the porcine genome, including the addition of genes for factors which suppress the rejection of transplanted porcine tissues and the inactivation or removal of undesirable genes which can only be accomplished at this time by targeted recombination and somatic nuclear transfer."