Pluripotent stem cells are capable of differentiating into cells of any tissue. The fact that iPS cell lines can be produced from skin cells or blood cells and directed to differentiate into a desired direction makes it possible to investigate e.g. myocardial or nerve cells having a disease-associated genotype. This will enable the development of experimental models of disease mechanisms and also apply them to drug screening, which may allow the development of novel types of treatment. In the future it may become possible to replace injured cells of a patient with autologous iPS cell derived transplants.