While the role of tau in ALS is less well-established than for AD and PD, recent research has shown that a specific phosphorylated tau species, pTau-S396, is mislocalized to synapses (rather than the cytosol) in motor cortex neurons from postmortem brains across ALS subtypes [84], and also more abundant in both postmortem motor cortex and cerebrospinal fluid compared to controls [85]. Here, MAPT is linked to Parkinson disease.