Down-regulation of SNX27/retromer is strongly implicated in AD through increased intracellular production of β-amyloid peptides from endosomal APP breakdown (Nielsen et al., 2007; Lane et al., 2010; Fjorback et al., 2012; Willnow and Andersen, 2013; Huang et al., 2016; Milne et al., 2019). Here, SNX27 is linked to Alzheimer disease.