Christopher Michel · CC BY 4.0

Stanley Prusiner proposed that a class of infectious disease could be caused by a misfolded protein alone, with no DNA or RNA involved to carry the infection — an idea, which he named a prion, that much of the field initially treated as close to heresy. It held up: Prusiner won the 1997 Nobel Prize in Physiology or Medicine for the work, done at UCSF, where he founded the Institute for Neurodegenerative Diseases.