MAPT and tauopathy: Considering the concepts of prion research summarized very briefly above, it is noteworthy that tauopathies are (i) initiated by protein misfolding that templates further tau misfolding; (ii) tau misfolding progresses into adjacent cells and brain regions in a fashion that may account for the progression of clinical symptoms; (iii) various tauopathies present with different neuropathologies (e.g., see Table 1) and biochemistries reminiscent of strains.