While PrP-res, a truncated amyloid form of the host protein, can trap infectious particles in its aggregate matrix, and limit their release, the continued production of enormous levels of PrP-res after the FU-CJD agent is cleared has major ramifications for other neurodegenerative diseases, including Alzheimer’s Disease (AD). Here, PRNP is linked to early-onset autosomal dominant Alzheimer disease.