A prion (/ˈpriːɒn/) is a protein that can fold in multiple, structurally distinct ways, at least one of which is transmissible to other prion proteins. It is this form of replication that leads to disease that is similar to viral infection. The word prion, coined in 1982 by Stanley B. Prusiner, is short for “proteinaceous infectious particle” derived from the words protein and infection, in reference to a prion's ability to self-propagate and transmit its conformation to other prions.