which would have to be used post-operation to ensure that the body continues to accept the new organ, suppress the immune system. This makes the person more susceptible to infection. Pigs'DNA contains a virus that is harmless to pigs but could prove fatal to human. Fortunately, scientists have identified a type of pig that does not carry this virus as part of its DNA. Scientists are also working on ways to prevent the virus from replicating by identifying the receptors that allow the virus to enter a cell.