Figure 1 illustrates the tau spreading schemes in AD, PSP, and CBD, as suggested by pathology studies [16–21], although much uncertainty in the exact spreading patterns of tau remains, especially in non-AD tauopathies given the relative paucity of neuropathological data in those diseases in comparison to AD, as well as their neuropathological heterogeneity. Here, MAPT is linked to red-green color blindness.