It has been suggested that Notch1 participates in olfactory function (Brai et al., 2014), which is impaired in patients with Alzheimer disease (AD) (Berezovska et al., 1998; Moehlmann et al., 2002; Brai et al., 2016) and in experimental models of familial AD secondary to presenilin mutations (Okochi et al., 2002). Here, NOTCH1 is linked to Alzheimer disease.