Amyloidosis is a disease where plaques of the amyloid protein build up and impair tissue function. What causes the these plaques to form still remains unknown. Seen here is an image of an amyloid plaque from a heart stained to identify amyloid-forming protein (green) and other supporting materials (orange and blue).
Image by William Lewis, Emory University School of Medicine.
I also read a study relating this to Alzheimer’s