DKK1 is known as antagonist of the canonical Wnt signalling pathway.It can block canonical Wnt signaling by combining with Kremen and Lrp6 transmembrane receptor.Moreover, a specificity and high level expression of DKK1 could be measured in multiple lung cancer cell lines and lung cancer tissues.Thereby, both DKK1 and other biomarks can increased sensitivity to detect lung cancer.Our previous study, however, found that activity of DKK1 promoter in lung cancer cells is low.