Prions are the causative agents of progressive neurodegenerative disorders that affect both humans and animals. Like viruses, prions are acellular, however unlike viruses, bacteria, or other parasites, they contain no nucleic acid genome, and so individual prions are not capable of replication. Yet, they are able to transmit from one person or species to another via a mechanism that results in prion amplification (infectious). What are prions made of? Described the mechanism used by prions that results in amplification of prion molecules.