Bruce Rahn, a professor at the University of Chicago in the United States, predicts that in medicine, it will be possible to supply transplanted organs in unlimited quantities, and human beings no longer need dead people to donate organs.

Those organs for transplantation will be grown and cultured in animals, such as pigs. Different animals are used to grow different organs, but they may also be developed from human stem cells. When a patient needs a new kidney, surgeons can contact commercial organ manufacturers, who can provide organs that match the patient. Except for one organ, that is the brain.

Ellen Haber Katz, a professor at the West Institute in Philadelphia, USA, further predicted that the human body can realize the routine replacement of certain organs through some regenerative drugs without transplantation. This treatment will be first applied to the regeneration of disabled fingers or toes. After half a century's development, the whole limbs and spine of human beings can also be repaired.