We don't think it's miraculous when a cut finger heals on its own, or a sprained ankle becomes good as new over a matter of weeks. But what if arthritis or heart disease could be treated or prevented the same way — by using the body's natural healing powers? Now are we talking miraculous?

Not according to William Haseltine, CEO of Human Genome Sciences Inc., and the leading pioneer in the field of regenerative medicine. This emerging area involves harnessing the chemical signals the body uses to trigger cell repair and replacement.

"When we know, in effect, what our cells know, health care will be revolutionized, giving birth to regenerative medicine — ultimately including the prolongation of life by regenerating our aging bodies with younger cells," Dr. Haseltine told the New York Times in a November 2000 article.

Cells communicate with one another; they "discuss" when to make certain proteins, where the proteins should go, and what should happen when they reach their destinations. Dr. Haseltine and his colleagues at Human Genome Sciences claim to have identified the components of this amazing communication system - or the words used in this cellular "language" - and are in the process of discovering what each word might mean.

If Dr. Haseltine and his company can translate the cellular language, the possibilities for humanity are endless. For example, a protein called B-lymphocyte stimulator will be tested on people with defective immune systems, in hopes of boosting their levels of a type of white blood cell. A drug to block this protein could prove useful for people with certain autoimmune diseases, such as lupus and rheumatoid arthritis. Other proteins could be used to jump-start wound healing, replace diseased tissue, combat cancer, and just about anything else you can think of.

Regenerative medicine uses genes, proteins, and antibodies as medicines. Instead of getting a drug, a patient might receive a growth factor, gene therapy, hormone treatment, antibody treatment or other treatment. According to Dr. Haseltine, these types of treatments will make up half of all therapies in the next 20 years.

Regenerative medicine also involves using human cells to rebuild organs, either by injection into diseased tissues or by constructing new healthy organs outside the body as replacements. The latter concept, called autotransplantation, is under study by Dr. Haseltine and others; one he believes will soon be reality.

Stem cells are a mainstay of regenerative medicine. These cells are the "blank slates" of the body — they haven't committed to becoming a skin cell, heart cell or kidney cell. This type of research has focused on two primary areas: adult stem cells and human embryonic stem cells. Adult pluripotent stem cells have the potential to become many different types of cells. Human embryonic pluripotent stem cells are even more powerful: they are totipotent, capable of becoming any type of mature human cell.

Stem cells cannot only be coaxed down a certain life path (to become a heart muscle cell, for example, or a liver cell), they also can latch on to tissue in the body and become that type of tissue. Depending on how they are cultured, a type of adult stem cell called a bone marrow stromal cell, for example, can develop into bone cells or cartilage cells in the laboratory. Researchers believe that if these cells are given to people undergoing bone marrow transplants, they may help the bone marrow recover faster and thus make people healthier faster too.

Dr. Haseltine predicts that in the future regenerative medicine will be able to trigger the body to do what's necessary — eliminate a tumor, heal a wound, or re-grow lost neurons. We will be able to grow any tissue, regulate any cell signal and rebuild any organ. It may sound like impossible science fiction, but the body already does miraculous things on its own. Dr. Haseltine, and others, are just trying to understand how so that we can harness this incredible ability to self-heal and regenerate.