protsess, mille tulemusena polariseerunud epiteelirakud, mis normaalses olekus seostuvad alumise pinnaga basaalsele laaminale, teevad läbi rea biokeemilisi muutusi ning omandavad mesenhümaalsetele rakkudele iseloomuliku fenotüübi, The epithelial–mesenchymal transition (EMT) is a process by which epithelial cells lose their cell polarity and cell-cell adhesion, and gain migratory and invasive properties to become mesenchymal stem cells; these are multipotent stromal cells that can differentiate into a variety of cell types. EMT is essential for numerous developmental processes including mesoderm formation and neural tube formation. EMT has also been shown to occur in wound healing, in organ fibrosis and in the initiation of metastasis for cancer progression.