The controversy over the work of South Korean scientist Dr. Hwang Woo Suk continues to grow. Doubts about the credibility of his research is a blow not only to his many supporters in South Korea, but also to millions of people around the world who had hoped that his work held out cures for debilitating and life-threatening diseases. Dr. Hwang must answer the critics and end this dispute for his sake, for the sake of his country and for those who suffer from illness and disease.

Last year Dr. Hwang claimed he had made history by being the first person to clone a human cell. In plain terms, he removed natural DNA -- the genetic code -- from an egg and inserted DNA from another egg. Each of two new eggs then grew into an embryo. An embryo produces stem cells, which are capable of developing into every type of human tissue. The stem cells are considered clones, an exact genetic copy of an individual.

The significance of this breakthrough for medical science is hard to overestimate. Cloning allows a donor to generate new body parts. Since the DNA in the new tissue is the same as that of the recipient, his or her body would not reject it. This opens the door to entirely new ranges of therapies and treatments for previously untreatable diseases.