APP and early-onset autosomal dominant Alzheimer disease: With regard to the role of APP processing in Alzheimer’s disease, recently published work suggests that an imbalance between Wnt3a/canonical signaling pathway and the Wnt5a/PCP signaling pathway at the initial step of amyloid beta production could trigger a vicious cycle favoring the amyloidogenic processing of APP (Sellers et al., 2018; Elliott et al., 2018).