Your best friend is in the hospital. He needs a liver transplant. The liver he is getting does not come from another human being. It is coming from his clone. Several years ago he was cloned.
Cloning is the making of an exact copy of an organism.
Thus the genes and all the parts of the clone are identical to those of the original organism. Thousands of people desperately need to replace a failing organ with a healthy one. These healthy organs come from people that agreed to donate them upon their death. Some, like bone marrow and kidneys, may come from living donors. Unfortunately, we have a very short supply of organs for transplants.