DKK1 and Alzheimer disease: Finally, the AD-associated protein Clusterin (Harold et al., 2009; Lambert et al., 2009) is involved in Aß-driven Dkk1 expression, as soluble Aß promotes the intracellular accumulation of Clusterin and subsequent Dkk1 upregulation, whereas knock-down of Clusterin prevents induction of Dkk1 expression and protects against Aß neurotoxicity (Killick et al., 2014).