DKK1 and Alzheimer disease: Cultures from 3xTg-AD mice transfected with miR-431 followed by treatment with Dkk1 showed a significantly higher number of presynaptic sites (116.7 ± 12.12, n = 9) in comparison to cultures treated with Dkk1 and negative miRNA mimic control (52.17 ± 7.788, n = 7, p < 0.0001) (Figure 1A).