Many millions of adult stem cells are found in every human. Our body uses stem cells as one way of repairing itself. Studies have illustrated that if adult stem cells are harvested and then injected at the site of diseased or damaged tissue, reconstruction of the tissue is feasible under the right circumstances. These cells can be collected from blood, fat, bone marrow, dental pulp, skeletal muscle and other sources. Cord blood provides yet another source of adult stem cells. Scientists and clinicians are developing and refining their ability to prepare harvested stem cells to be injected into patients to repair diseased or damaged tissue.