Here is another major difference: "We know that the β-A4 amyloid of Alzheimer’s disease also derives from a normal host protein that in diseased people accumul

Here is another major difference: "We know that the β-A4 amyloid of Alzheimer’s disease also derives from a normal host protein that in diseased people accumulates in the brain, but it does not have the ability to transmit disease to a healthy person. Why this difference?" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1114482/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1114482/