Abstract: Tauopathies are a group of neurodegenerative diseases characterized by abnormal metabolism of the misfolded tau protein. Tau is encoded by the microtubule-associated protein tau gene (MAPT) and can be classified as either 3-repeat (3R) or 4-repeat (4R) based on the number of repeat domains from alternative splicing of exon 10 of the MAPT gene. Tauopathies are subdivided into primary tauopathies and secondary tauopathies (Chung et al., 2021). Primary tauopathies involve tau protein aggregation and tangling as a predominant feature. Primary tauopathies exhibit clinical heterogeneity, and their neuropathological features guide definitive diagnosis. Examples of primary tauopathies include progressive supranuclear palsy, frontotemporal dementia, Pick’s disease, chronic traumatic encephalopathy, corticobasal degeneration, primary age-related tauopathy, aging-related tau astrogliopathy, globular glia tauopathy, tangle-only dementia, and argyrophilic grain disease. Secondary tauopathies, such as Alzheimer’s disease (AD) and Down’s syndrome, feature tau protein aggregates coexisting with other protein abnormalities.