The deposition of microtubule-associated protein tau (MAPT/tau) into insoluble fibrils is a major pathological hallmark of fatal and incurable neurodegenerative diseases—including Alzheimer’s disease (AD), frontotemporal dementia (FTD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and others1–3. This evidence concerns the gene MAPT and progressive supranuclear palsy.