Last week, clinical researchers began to find out what the consequences of the death of a teenager last fall in a gene therapy experiment at the University of Pennsylvania would be for Penn--and for national policy. Several federal agencies put forward proposals for sharply increasing the surveillance of human trials, especially those involving the use of viral carriers in gene therapy. And Penn, which has been in the hot seat for several investigations, announced a more rigorous system for approving and monitoring the use of human subjects that could add significantly to the cost of some types of academic research.