Abstract: Importance of TAU protein for dementia syndromes: Dementia currently affects about 55 million people worldwide, with Alzheimer´s disease (AD) being the most prevalent form. The one crucial pathological hallmark of AD that correlates best with loss of synapses and cognitive decline are the so-called intracellular neurofibrillary tangles composed of mislocalized/missorted and hyperphosphorylated TAU protein (Naseri et al., 2019). Many other neurodegenerative diseases, both genetic and non-genetic, are characterized by neurofibrillary tangles or pathological accumulation of the protein TAU and are thus termed “tauopathies”. Tauopathies include AD and related aging-associated dementia syndromes like frontotemporal dementia and variants thereof (progressive supranuclear palsy, Pick‘s disease, corticobasal degeneration), but also childhood-onset genetic diseases (Zimmer-Bensch and Zempel, 2021).