The pathological process amyloidosis, in which misfolded proteins (amyloids) form insoluble fibril deposits, occurs in many diseases, including Alzheimer disease (AD) and type 2 diabetes mellitus (T2D). However, little is known about whether different forms of amyloid proteins interact or how amyloid formation begins in vivo. A new study has found evidence that amyloid from the brain can stimulate the growth of fibrils in the murine pancreas and pancreatic-related amyloid can be found along with brain-related amyloid in human brain senile plaques.