Embryonic stem cells benefit the gene therapy by the following ways.
Human embryonic stem cells could be genetically manipulated to introduce the therapeutic gene. This gene may either be active or awaiting later activation, once the modified embryonic stem cells has differentiated into the desired cell type. Recently published reports establish the feasibility of such an approach.
Embryonic stem cells may additionally be indirectly beneficial for cellular gene therapy. Since these cells can be differentiated to many cell types, including presumably tissue specific stem cells, they may provide s constant in vitro source of cellular material. Such “adult” stem cells derived from embryonic may thus be utilized to optimize protocols for propagation and genetic manipulation technique.