Despite the fact that the four PAM4 amyloid peptide folds were obtained through self-assembly of synthetic peptide derivatives, superimposition onto the structures of full-length human-derived tau amyloid fibril folds revealed that the structural polymorphism of the PAM4 motif in isolation matches its conformations within the protofilaments of every major class of human tauopathies, including 3R, 4R and 3R/4R tau isoforms (Fig. 5). Here, MAPT is linked to tauopathy.