The recent tragic and widely publicised death of Jesse Gelsinger in a gene therapy trial has many important lessons for those engaged in the ethical review of research. One of the most important lessons is that ethics committees can give too much weight to ensuring informed consent and not enough attention to minimising the harm associated with participation in research. The first responsibility of ethics committees should be to ensure that the expected harm associated with participation is reasonable. Jesse was (...) an 18-year-old man with a mild form of ornithine transcarbamylase (OTC) deficiency, a disorder of nitrogen metabolism. His form of the disease could be controlled by diet and drug treatment. On September 13 1999 a team of researchers lead by James Wilson at the University of Pennsylvania's Institute for Human Gene Therapy (IHGT) injected 3.8 X 1013 adenovirus vector particles containing a gene to correct the genetic defect. He was the eighteenth and final patient in the trial. The virus particles were injected directly into the liver. He received the largest number of virus particles in a gene therapy trial.1 Four days later he was dead from what was probably an immune reaction to the virus vector. This was the first death directly attributed to gene therapy. It resulted in worldwide publicity, an independent investigation, the Federal Drug Administration (FDA) suspending all trials at the IHGT, an FDA, and a senate subcommittee investigation. At a special public meeting at the National Institutes of Health (NIH) in December 1999, James Wilson, also the director of the IHGT, said they still did not understand fully what had gone wrong.2 Even though a massive dose had been used, only 1% of transferred genes reached the target cells. (None of the patients in the trial showed significant gene expression. Art …. (shrink)