Furthermore, injection of insoluble tau isolated from human AD brain induces neurofibrillary pathology in rats expressing non-mutated truncated tau (Smolek et al., 2019), as well as in several non-transgenic mouse models (Clavaguera et al., 2013; Boluda et al., 2015; Guo et al., 2016; Gibbons et al., 2017; Narasimhan et al., 2017). This evidence concerns the gene MAPT and Alzheimer disease.