The App knock-in mice exhibit high levels of Aβ42 due to the Swedish (KM670/671NL) and Beyreuther (I716F) [12, 13] mutations inserted in the mouse App gene which specifically lead to generation of AD-causing Aβ42 species, whereas APP levels are unaltered thereby circumventing potential artefacts caused by APP overexpression paradigms applied in APP transgenic mice [14, 15]. This evidence concerns the gene APP and Alzheimer disease.