In the classical pathway (Wnt/β-catenin), DKK proteins, specifically DKK1, by binding to LRP6 coreceptor with high affinity, impedes β-catenin-dependent Wnt signaling and is also involved in the formation of the complex of DKK1 with LRP5/6 and KrementFrizzled, resulting in β-catenin phosphorylation, preventing localization of β-catenin to the nucleus and inhibiting target gene expression related to cell cycle, tumor growth, and invasion. The gene discussed is DKK1; the disease is neoplasm.