WIF1 and cancer: PDAC patients often have several mutations of the Wnt ligands, and epigenetic silencing of extracellular Wnt inhibitors, such as WIF-1 and DICKKOPFs (DKKs) may prompt the stabilization and accumulation of β-catenin in cancers despite mutational activation of Wnt/β-catenin signaling [27–29].