Among the several components of the Wnt pathway that are altered in AD, increased levels of Dkk1 were found in post-mortem brains of AD patients (Caricasole et al., 2004), and in the hippocampus of the TgCRND8 mouse model of AD (Rosi et al., 2010), expressing a double mutant form of the human APP. Here, APP is linked to Alzheimer disease.