MAPT and Alzheimer disease: Goetzl et al. (2015, 2018) measured the levels of different pathogenic proteins, Aβ-amyloid, total tau and p-tau isoforms inside NDEs immunoprecipitated with L1CAM to isolate specifically neuronal exosomes from blood of AD, Mild Cognitive Impairment (MCI) and controls (Kapogiannis et al., 2015).