The honest answer to this question is no, there is never a guarantee for success in any medical treatment. This is no different for renown or novel treatments such as stem cell therapy. A number of factors determine success, such as overall health status of the patient, complexity of the disease, as well as interaction of the stem cells with the patients’ immune system. However, stem cells are well researched by now, and thousands of applications worldwide prove their meaningfulness in the treatment of a wide variety of diseases.