Where does gene therapy go?

Gene therapy, as well as the human genome project, expresses the implicit b elief of our generation that improvement of human life supposes a better un derstanding of the mechanisms operating in living organisms. After 15 years of major endeavor, what has all this gene therapy work brought? which diff iculties are we facing? how can we imagine the future of the field? altoget her, can we keep on with our belief? This paper reports discussions organiz ed around those questions. For a more direct description of gene therapy st udies, readers could refer to the special issue published by medecine/scien ces in May 1999.