Trypsin-resistant amyloid cores of tau fibrils from AD, PiD, CBD and PSP have unique fragment patterns when separated by gel electrophoresis, suggesting that each disease contains a distinct assembled tau conformer/strain.4 Atomic-resolution structures of these amyloid cores have been mapped using cryo-electron microscopy (cryo-EM), establishing the existence of distinct conformers of fibrillar tau in AD,5 PiD,6 CBD7 and chronic traumatic encephalopathy (CTE).8 The gene discussed is MAPT; the disease is Alzheimer disease.