Can a lab that accidentally leaks an enhanced virus undo that mistake? Gain-of-function on dangerous pathogens means making them more transmissible or lethal. The burden of proof belongs to those who want to do it: show a concrete, urgent benefit that cannot be achieved with safer methods. My opponent will say it prepares us for outbreaks, but that's speculative. A single containment failure could kill millions. We don't ban research generally; we ban this specific high-risk category. The 2014 moratorium was a sensible precedent. When the downside is a pandemic, the precautionary principle should govern.