MAPT and Alzheimer disease: All AD-inoculated lemurs developed intraneuronal tau accumulations resembling neurofibrillary tangles (NFTs, Fig. 6a–d) and neuropil threads (NTs, Fig. 6e–h), at the inoculation sites and in several other regions (Figs. 4b, g–j, Figs. 7, 8 and 9).