Unfortunately, mixed chimera remains an extremely interesting and
fascinating biological observation, which is not immediately applicable
as a target for future medical treatments. However, it is a
supporting observation, which may affect future developing gene
therapy trial. It is a distinct possibility that, if researchers were able
to transfer an efficient ß gene inside the thalassemic HSC, with this
gene achieving a good level of expression, it would not be necessary
to replace the entire diseased bone marrow to obtain clinical
correction of the disease. In theory, with a 100% expression of the
transfected-modified gene, a limited (20%) autologous genemodified
engraftment could be sufficient to obtain the required
clinical effect.