They are: (1)—AD and AACD are caused and driven by intra- rather than extracellular Aβ; (2)—AD (but not AACD) is a two-stage disease; (3)—the symptomatic second stage of AD is driven by iAβ produced in the AβPP-independent pathway; (4)—iAβ generated independently of AβPP is retained intraneuronally, perpetuates its own production and renders AβPP-derived iAβ irrelevant for the progression of AD due to its marginal (in comparison with iAβ produced independently of AβPP) contribution into the cellular iAβ pool. Here, APP is linked to Alzheimer disease.