[Stem cell biology and therapeutic hopes: forbidden game?]

Stem cell biology is one of the most exciting subjects in life science nowadays. The major point in stem cell biology is the extraordinary capacity of these cells to self-renew and to give rise to different cell types. Nevertheless, major issues remain to be cleared and very few diseases can actually be cured based on stem cell therapy. Adult stem cells remain difficult to locate, isolate and amplify in a homogeneous fashion and, thus, limit their therapeutic application in clinical trial. Embryonic stem cells could represent a new hope in stem cell therapy but in addition to the scientific difficulties, over ethical and judiciary issues should be addressed. In order to cure routinely patients, controlled conditions for stem cell isolation, amplification, differentiation, and administration must be defined and effective tissue integration have to be established. In this review we will discuss these different aspects of stem cell biology.