In the earliest studies, brain homogenate or intracerebral fluid from tauopathy patients (including PiD, AGD, PSP, and CBD) was injected into mice expressing the longest isoform of human tau (2N4R), which resulted in the formation of inclusions that were reminiscent of what was observed in patients, with the exception of PiD [267]. Here, MAPT is linked to argyrophilic grain disease.