Expression and Role of Dickkopf-1 (Dkk1) in Tumors: From the Cells to the Patients.

() is a secretory antagonist of the classical Wnt signaling pathway. Many studies have reported that is abnormally expressed in tumor cells, and abnormal expression of can inhibit cell proliferation or induce apoptosis through pro-apoptotic factors, However, due to the differences in tumor environment and the complex regulatory mechanisms in different tumors, has different effects on the progression of different tumors. In many tumors, high expression of may promote tumor metastasis. However, , which is highly expressed in other tumors, can inhibit tumor invasion and metastasis. More and more evidence shows that plays a complex and different role in tumor occurrence, development and metastasis in different tumor environments and through a variety of complex regulatory mechanisms. Therefore, may not only be a useful biomarker of metastasis, but also a target for studying the metabolic mechanism of tumor cells and treating tumors in many tumor types. Therefore, this article reviews the research progress on the expression, mechanism and function of in different tumors, and at the same time, based on the public database data, we made a further analysis of the expression of in different tumors.