Prion Proof? Evidence grows for mad cow protein

Even as scientist Stanley B. Prusiner was accepting a Nobel prize in 1997 for linking misfolded proteins to certain brain diseases, doubters were pointing out that no one had ever actually shown that these proteins—which Prusiner dubbed prions—could cause infection.

Prusiner, a neurologist and biochemist at the University of California, San Francisco (UCSF), and his colleagues now report results that could silence many of his critics.