Bioengineering, e.g. successful manipulation of these cells with multipotential capacity of differentiation toward appropriate patterns and precise quantity, are the prerequisites for successful outcome and treatment. By combining in vivo and in vitro techniques, it is now possible to manage the wide spectrum of tissue damages and organ diseases. Although the stem-cell therapy is not a response to all the questions, it provides more and more answers every day. is a concise review on the functional, phenotypic, regenerative, transplantational and curative aspects of a stem cell’s entity. It is critical and encouraging at the same time, providing truthful and appropriate samples from the practice and research that can lead toward optimal use of this immense source of adjuvant and curative therapy in human pathology. Written by a clinician and a researcher, who are currently teaching what they are doing, it is recommended as a teaching tool along with an original textbook.