PSEN1 and Alzheimer disease: For AD research and medicine development, APPswe/PS1dE9 double transgenic mice (APP/PS1 for short) expressing a chimeric mouse/human APP695 with the Swedish mutation (KM594/595NL), together with a mutant human PS1 protein with E9 deletion were constructed by Jankowsky’s lab (Jankowsky et al., 2001).