MAPT and red-green color blindness: In the same study using multiplex immunohistochemistry and novel tau-cleaved D402 and D13 mentioned above, Theofilas et al. showed that caspase-6 truncated tau is abundant in AD, to a lesser extent in PiD, and almost absent in 4R tauopathies (PSP, CBD, and AGD) in both neurons and glia [7].