“Mice bred to develop a progressive Alzheimer’s-like disease as they aged (called APP/PS1 mice) were given daily injections of the protein, and it appeared to not only clear out the toxic amyloid plaques that are thought to trigger Alzheimer’s in humans, it also prevented more from forming.”
http://www.sciencealert.com/new-protein-injection-reverses-alzheimer-s-symptoms-in-mice-in-just-one-week
http://www.pnas.org/content/early/2016/04/13/1604032113.full (original PNAS article)