MAPT and Alzheimer disease: In addition, pathological tau and amyloid protein accumulations have been demonstrated in the olfactory epithelium/mucosa (OE) (Lee et al., 1993) and olfactory end-terminals including the entorhinal cortex (EC) in AD patients (Näslund et al., 2000; Desikan et al., 2012; Khan et al., 2014).