title: Gene and stem cell therapy: alone or in combination?
abstract: BACKGROUND
  Both gene and stem cell therapies hold great promise in the treatment of many genetic diseases and are currently focus of interest for many investigators. While both approaches are offering great and valuable treatment options for devastating and life-threatening diseases, they hold much greater promise in combination.
  
  
  METHODS
  As there are multiple options in selecting gene transfer vehicles among the non-viral and viral vectors, there are also many options among the different transplantable cell types ranging from lineage-restricted progenitor cells to multipotent and pluripotent stem cells. Here, combination of the gene therapy and stem cell therapy is discussed.
  
  
  RESULTS
  Several suc-cessful gene and stem cell therapies have been reported both in animal and human trials. Combination of the gene therapy and stem cell therapy can be carried out sequentially where the cell transplantation and the in vivo gene therapy are accomplished one after the other; or, as it is more commonly practiced, they can be carried out as ex vivo gene therapy where the transplantable cells are genetically modified outside the body before being transplanted into the body.
  
  
  CONCLUSIONS
  The combination of the stem-cell technology with gene therapy has the potential of providing both regenerative tissue and therapeutic material simultaneously; therefore, having the benefits of both technologies.
authors.affiliation: Department of Neurology, Jefferson Medical College, Philadelphia, Pennsylvanian 19107, USA.
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Rafi
keywords: Cell Therapy; Gene Therapy; Stem Cells