DKK1 and cancer: WNT-induced signaling, which is frequently involved in cancer progression, can be suppressed by DKK1.6,29–31 In addition, DKK1 has been shown to be activated during the progression of multiple tumors, including HCCs.7 Moreover, Yu et al.20 reported that increased expression of DKK1 is associated with cytoplasmic/nuclear β-catenin accumulation in HCC patients.