APP and Alzheimer disease: Results from previous studies have shown that netrin-1, via its interaction with amyloid precursor protein (APP, from which Aβ, the main component of the amyloid plaques associated with AD is derived) (Lourenço et al., 2009; Rama et al., 2012; Borel et al., 2017), suppresses Aβ peptide production as demonstrated both in vivo and in vitro.