MAPT and red-green color blindness: While AD and chronic traumatic encephalopathy (CTE) have distinct tau filaments contain both 3R and 4R tau (Fitzpatrick et al., 2017), tau filaments from PiD consist of residues Lys254–Phe378 of 3R tau (Falcon et al., 2018b) and those from CBD have four-layered fold with a large non-proteinaceous density (Zhang et al., 2020).