Although the importance of epithelial to mesenchymal transition (EMT) is acknowledged in tumor metastasis, the contribution of the reverse process—MET—to cancer progression has been unclear. A new study shows that the miR-200 family regulates MET and metastatic colonization in breast cancer, suggesting that flexible transitions between EMT and MET, or epithelial-mesenchymal plasticity, may be crucial at different stages of metastasis (pages 1101–1108).
