1995), and later by Alzheimer in 6 patients. Eighty years later, major components of these tangles were found to be comprised of hyperphosphorylated, filamentous tau (Grundke‐Iqbal et al. 1986). This was furthered by the discovery that the microtubule‐associated protein tau (MAPT) gene causes a fronto‐temporal dementia with Parkinsonism, which added genetic evidence that dysfunction in tau was sufficient in the absence of Aβ to cause neurodegeneration (Spillantini et al. 1998). Here, MAPT is linked to Parkinson disease.