For the first time, an antidote has been found to carbon-monoxide poisoning. Ling Wang and Qinzi Xu of the University of Pittsburgh in Pennsylvania and collaborators gave mice air containing 3% carbon monoxide for 4.5 minutes, which would kill most humans. The mice recovered when given a modified neuroglobin (a protein found in the brain and retina that protects cells by binding with oxygen and nitric oxide) that was engineered to bind to carbon monoxide 500 times more tightly than it binds to hemoglobin. The US Food and Drug Administration has promised an expedited review of the work.