Stanley Prusiner won the Nobel Prize in Physiology or Medicine in 1997 for his work in proposing an explanation for the cause of bovine spongiform encephalopathy ("mad cow disease") and its human equivalent, Creutzfeldt–Jakob disease. In this work, he coined the term prion, which comes from the words "proteinaceous" and "infectious," in 1982 to refer to a previously undescribed form of infection due to protein misfolding.