Decisive therapeutic advances are expected from the types of human embryo cells recently isolated, in replacing damaged tissue and organs and treating serious chronic diseases such as Parkinson’s disease, diabetes, multiple sclerosis, and so on. The possible production of these cells by cloning would also make it possible to resolve the problems of rejection routinely encountered in transplant surgery. A pertinent question is whether these scientific advances justify changing the rules under which very strict limits are placed on research and experiments in France concerned with the human embryo. Parliament will be faced with this question during the forthcoming review of the law of 29 July 1994, and it is to provide relevant background information that this report reviews knowledge and practices in the field of cloning and cell therapy. Cloning is considered from the standpoint of its therapeutic applications, for example the production of pharmaceutical proteins or of organs that are "humanised" by means of genetic transfer, or the – as yet hypothetical – creation of immuno-compatible embryo cells. As regards cell therapy, the study draws a distinction between applications that have already been proved (strains of haematopoietic cells, and skin grafts) experiments now in progress (grafts of hepatocytes, pancreatic cells and foetal neurones) and the prospects opened up by such cells whether taken from the embryo or the adult organism. Some recent discoveries concerning the plasticity of adult cells highlight the need for multi-disciplinary research to determine which category of base cells – embryonic or adult – will be the most appropriate for treating different types of pathology. After describing the commercial strategies now being applied in the English-speaking world and analysing the legislative easing now under consideration in the United States and the United Kingdom, the report describes the legal, economic and financial measures that have already been or could be taken to enable French research to compete internationally.