MAPT and Alzheimer disease: The fibrilgrowth occurs in a direction perpendicular to this double C-type structure,and infinitely many fragments are aligned in parallel to make up forthe insoluble neurofibrillary tangles (refer to Figure 1a).10 Interestingly,the tau fibril structure reported from a CTE brain (will be referredto as CTE-tau) also had a similar structure except that it had a wideropening in the closed region (refer to Figure 1b) and more open space within the closedfilaments.11 Later we will discuss aboutthe alignment of structures of AD-tau and CTE-tau.