The general role of this glycoprotein family specifically DKK1/2/4 has been determined as inhibitors of Wnt/ β-catenin pathway which has critical role in embryonic development, cell proliferation and migration, However, the activators effect of DKK2 on Wnt signaling has been demonstrated as much as its inhibitory action, Given that Wnt signaling pathway is a double edged sword in cancer progression, the exact role of DKK family in carcinogenesis has been remained unclear, as well. This evidence concerns the gene DKK2 and cancer.