MAPT and tauopathy: The isoform specificity and pathological features of tauopathy brains have been reported to be reproduced in seeded tau aggregation and pathology formation in in vitro and in vivo models using patient-derived tau seeds.28–33 Disease-defining tau filaments were also seen in multiple cases and in multiple brain regions in one individual, supporting the idea that templated amplification of tau filaments can occur in the patient’s brain.12,34–36 However, the involvement of PTMs in templated tau seeding and tau strain formation remains unclear.