Given the importance of Wnt/β-catenin signaling in promoting osteosarcoma progression, the DKK3 acting as an extracellular Wnt/β-catenin inhibitor, as well as a 3′-UTR sequence of DKK3 complementary to the seed sequence of miR-214-3p being identified by targetscan online analysis (http://www.targetscan.org/) (Fig. 2A), we hypothesized that miR-214-3p may degrade DKK3 by binding to its 3'-UTR and achieve the role in promoting the oncogenesis and development of osteosarcoma. The gene discussed is DKK3; the disease is osteosarcoma.