After a presentation of their assessment report of the Bioethic law, as it was stipulated in its article 40, the reporters – MM. Claeys and Vialatte – are now following-up their study, on the basis of a second legislative reference, according to the article 26 of this law. It aims at carrying-up a report assessing the respective results of research into embryonic stem cells and mature stem cells, in the perspective of an examination of these provisions by Parliament. The 2004 French law prohibits, in principle, research into embryo and human embryonic stem cells. However, and since February 2006, exceptional authorization may be granted, for a period of 5 years, after consent given by the parents and under certain conditions : that research be able to assure major therapeutic progress and that no other alternative method with an equal efficiency exist, in the present state of the scientific knowledge.