CDK5 and Alzheimer disease: We analyzed three separate mouse models of Alzheimer’s disease and neurodegeneration: (i) CK‐p25 (Cruz et al, 2003, 2006; Fischer et al, 2005), a model of p25/Cdk5 activation in forebrain neurons; (2) 5XFAD (Oakley et al, 2006), a model of Aβ toxicity; and (ii) Tau P301S (Ghetti et al, 2002), a model of phospho‐Tau and neurofibrillary tangles.