PSEN1 and Alzheimer disease: Post-mortem human brains and brains from APPswe/PS1ΔE9 mice (transgenic model of AD, made by the insertion of human APP and presenilin 1 (PS1) genes known to cause familial AD) also show impaired insulin signaling (measured by immunohistochemistry (IHC) and western blotting (WB) techniques, respectively) in the hippocampus [74].