The next MTBE: Contamination from fuel additives could spread.

3 4 2 N O V E M B E R 2 9 , 2 0 0 3 V O L . 1 6 4 Md. “It’s absolutely amazing how quickly they did this.” Until now, ACE2 has largely interested cardiologists. Several decades ago, physicians began using inhibitors of a similar enzyme, ACE, to treat high blood pressure and heart disease. A few years ago, scientists discovered ACE2 and began to look for compounds that block its activities. There’s a good correspondence between tissues that make ACE2—the heart, lungs, and kidneys, for example—and ones affected by the SARS virus, notes Farzan. He and his colleagues are now looking into whether known ACE2 inhibitors block the SARS virus from cells. It’s possible that these inhibitors may thwart ACE2’s function but still allow the virus to grab onto the enzyme, cautions Farzan. Gary Nabel, director of the National Institutes of Health Vaccine Research Center in Bethesda, Md., calls the new work a “fascinating discovery” but notes that the SARS virus may exploit proteins other than ACE2 as receptors. —J. TRAVIS