Hematopoiesis and Gene Therapy : Springer : 9780306459627 : 0306459620 : 31 Mar 1999 : Since the first concepts of gene therapy were formulated, the hemopoietic system has been considered the most natural first target tissue for genetic manipulation. The reasons for this include the fact that a very large number of inherited disorders (including some of the most common disorders, such as the hemoglobinopathies) are disorders of the hemopoietic system, and the large amount of experience in hematopoietic transplantation biology. The consequence of this resulted in the first clinical trial of gene therapy in 1989, where two children suffering from severe combined immune deficiency (ADA-SCID) were transplanted with T-cells express­ ing adenosine deaminase (the defective enzyme in patients with this disorder). The partial success of this treatment was perhaps responsible for undue optimism among those proposing other gene therapy treatments within the hematopoietic system, and it has since