The expression and roles of DKK-1 are different in various cancers, current studies have reported that overexpression of DKK-1 is found in many malignant tumors, including lung cancer, esophageal carcinomas, cervical cancer, and hepatocellular carcinoma (HCC), indicating a potential oncogenic function of DKK-1 [10-13]. This evidence concerns the gene DKK1 and lung cancer.