Stem cell therapy, also known as regenerative medicine, is the use of stem cells to treat or prevent a disease or condition. Stem cells grown in a lab are manipulated to specialise into specific types of cells, such as heart muscle cells, blood cells or nerve cells. The specialised cells can then be implanted into a person. For example, if the person has heart disease, the cells could be injected into the damaged heart muscle. The healthy transplanted heart cells could then contribute to repairing defective heart muscle.