Then, we found Wnt antagonist genes DKK2 and FRZB were upregulated by circCNIH4 overexpression in MKN-74 and HGC-27 cells and proved that circCNIH4 played its function by regulating DKK2 and FRZB expression and inactivating Wnt/β-catenin pathway in gastric cancer cells. The gene discussed is DKK2; the disease is gastric cancer.