The evolution of clinical peripheral blood stem cell transplantation.

Our growing physiological understanding of hematopoietic progenitor cells has led to the clinical use of circulating progenitor cells, including stem cells, for either reconstitution of hematopoietic function, up to the transduction of functional genes into a self-renewing cell system. In the following, an attempt has been made to recollect the major steps in the evolution of clinical blood stem transplantation, from the morphological description of small lymphocytes circulating in the blood up to somatic gene therapy covering a time period of 87 years.