APP and Alzheimer disease: While smaller than the body of literature covering APP processing, there are many reports of gamma‐secretase independent functions of presenilin in regulating several biological pathways that are disrupted in AD, such as calcium homeostasis, mitochondrial and lysosomal function, and autophagy (Area‐Gomez et al., 2012; Bezprozvanny & Mattson, 2008; Cheung et al., 2008; Lee et al., 2010; Neely et al., 2011; Nelson et al., 2007; Reddy et al., 2016).