>> no, it's important to understand the intent of the research and the effect of the research. so the intent of the research was to understand whether certain bat coronavirus spike proteins could infect human cells. and the way they did the experiment was they took a well-known bat coronavirus called wiv-1 and added to that some other bat coronavirus spike proteins. and they gave that to mice altered to have the receptor, the ace-2 receptor that the virus uses to enter human cells. they found, yes, they could. those spike proteins could enter human cells, but they also noticed that the enhanced virus then was more virulent. >> okay. >> so they proved that those spike proteins could enter human cells but in so doing they made the virus they used more deadly essentially. the mice were sicker.