system
Given the following post, respond as if you're commenting on Reddit:
human
What is a double prion?
gpt
Prions are proteins that re-fold into a three dimensional form in which that protein is harmful to health. Alzheimer’s disease may be caused by two proteins that together cause the disease. Hence a double prion disease.  Amyloid beta and tau are both prions that are implicated in Alzheimer’s.