This (r)evolution to clinico-biological diagnosing is underway in the second most common neurodegenerative disorder—Parkinson's disease (PD) as well as atypical parkinsonian syndromes where a purely clinical diagnosing still is the gold-standard.40, 41, 42, 43 Biomarkers of protein aggregate pathology such as 3R/4R-tau real-time-quaking-induced-conversion (RT-QuIC)44 and alpha-synuclein RT-QuIC45 are probably the most sensitive and specific single diagnostic biomarkers for the determination of underlying pathology. Here, MAPT is linked to Parkinson disease.