Prions Fibrils (IMAGE) Università di Trento Caption Prions are unusual infectious agents made by aberrantly folded forms of a physiological protein called the cellular prion protein, or PrPC. Credit Spagnolli_Rigoli Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.