Résumé
Human embryonic stem cells (hESC) are derived front the inner cell mass (ICM) of the human blastocyst at day 5 or 6 of the early embryo development. These cells display two cardinal features: they are able to differentiate into cell types from many if not all human tissue (pluripotency) and they proliferate strongly and indefinitely without senescence in vitro. Therefore, hESC are a source of choice for stem cells for regenerative medicine and are a reference model to study the biology of pluripotency. Since 2004, the French law (loi de Bioethique) authorizes hESC research under certain conditions. (C) 2009 Published by Elsevier Masson SAS.