Figure 1

The epithelial-mesenchymal transition (EMT) occurs at the primary tumour site where epithelial cells lose tight junctions and apico-basal polarity. The remodelling of the cytoskeleton occurs as well. The invasion process through the extracellular matrix (ECM) is frequently led by so called tumour-associated fibroblasts. EMT can induce stem-cell-like properties in cells. The question still remains whether the existing cancer stem cells or rather those cells that escaped the primary tumour and acquired the stem cell like phenotype through the EMT process induce distant metastasis.