DKK1 and liver cancer: Although the augmented transcriptional activity of Tcf4/β-catenin complex by inactivation mutations in APC or AXIN2, or activating mutations in CTNNB1 may not be affected by the suppression of frizzled receptors, complex network of signaling pathways may render undetermined characteristics to colorectal and liver cancer cells, as restoring expression of SFRP4 and DKK1 in colorectal cancer cells attenuates Wnt signaling [44], [45].