EMT and MET in Metastasis: Where Are the Cancer Stem Cells?

Activation of epithelial-mesenchymal transition (EMT) is important for cancer cell dissemination. Two papers in this issue of Cancer Cell (Ocaٌa and colleagues and Tsai and colleagues) support the concept that the reversal of EMT is necessary for efficient metastatic colonization. Moreover, although EMT has been associated with stemness properties, one study indicates that they are not necessarily linked.