the main molecule that really defines the incompatibility of an organ tween a pig and a human. when a pig organ has been transplanted up the evolutionary scale, there has been this immediate rejection of the organ. within minutes to hours. and because of the revolution in genetic engineering of animals, you know, we have got ourfirst engineering of animals, you know, we have got our first hope that we could get beyond that initial barrier. all of the laboratory tests and everything that we did all looked pretty normal, in terms of what we would expect when we did a human transplant, so two things. no evidence of this vigorous early