Embryonic stem cells: from bench to bedside.

As early as their derivation, embryonic stem (ES) cells have attracted a great attention to clinicians. Derived from early embryos, these cells remain pluripotent in culture while they can be expanded in principle without limit. They give rise to most progenies and differentiate to all major somatic lineages of potential use in regenerative medicine. The great therapeutic promises put forward almost 10 years ago to cure or relieve degenerative diseases are still up to date. However, cell therapy is a complex process that significantly differs from drug-based medicine. Although a clinical trial has been announced by GERON for next year to cure spinal cord injury, many issues remain to be addressed at the bench before these cells can be used in clinics.