DKK1 and Alzheimer disease: As part of the first impairment in the Wnt signaling pathway reported in this study, enhanced GSK3β kinase activation was found beginning at the presymptomatic stage of the pathology in 2-3-month-old 3xTg-AD mice, similar in magnitude to what occurred until 9–12 months of age in the WT animals, correlating with the induction of the Wnt antagonist Dkk-1.