Prions behave a bit like a biological version of ice-nine. It's a novel shape of protein that "teaches" other protein to be shaped like it. Obviously its scope

Prions behave a bit like a biological version of ice-nine. It's a novel shape of protein that "teaches" other protein to be shaped like it. Obviously its scope is far more limited than all the world's water, but it's still sobering to think that this risk even exists.