Dickkopf-1 helps metastasis by immune evasion

Cancer metastasis still remains leading cause of cancerrelated death. To diminish the rate of cancer-related death, the critical issue is to deal with recurrences and chemoresistance. Metastasis consists with sequential steps; tumor invasion, intravasation, extravasation and colonization in second organs. Accumulating evidence suggests that a cell population with stem cell-like tumor cells exists as dormant in the body. Once awaken from dormancy, the cells start growing. So far, it has been reported that dormant tumor cells are involved in metastasis (1,2). Does only a small population carry over the phenotype? How can dormant cells survive during tumor progression?