"http://www.ncbi.nlm.nih.gov/pubmed/25619882" An article published by researchers from the School of Pharmacy of the University of Lisbon and from the Molecular Biology and Biochemistry Research Centre for Nanomedicine (CIBBIM-Nanomedicine) from the Vall d'Hebron Research Institute (VHIR) includes the latest discoveries in the field of epithelial metastatic cancer and considers the possibility of opening new therapeutic fronts for the treatment of the breast cancer.The article, published in the specialized magazine Current Gene Therapy, focus on the process by which epithelial cells in the body become stem cells, process known as Epithelial Mesenchymal Transition (EMT), and what gene regulation strategy could be used to control this process in tumors, reducing the dangerousness of the breast metastatic cancer.EMT is useful to conceive organs, to regenerate tissues or for the wound healing, but it also plays a very important role in metastatic cancers with an epithelial origin. In this phenomenon, epithelial cancer cells lose their morphological features, acquiring the features of an undifferentiated cell, and get the propriety to survive without being attached to other cells. In consequence, undifferentiated cells are able to detach from the epithelial tissue and travel through the blood to colonize other tissues where they establish and develop the metastasis.Many intracellular changes are necessary for this process, and they are, then, clue elements in the regulation of the tumor’s invasive and metastatic capacity. Some of these regulatory factors are presented in this article as possible therapeutic target, taking into account they have different roles in each kind of tumor and in each tumor’s evolution stage. According to researchers, new methods of gene therapy could allow the modification of these regulatory factors’ expression, keeping the cancer in its early stages, before they become undifferentiated, when the cancer is more sensible to the chemotherapy. This would allow control cancer’s invasive potential and raise the efficacy of the treatment because, often, cells that suffer this phenomenon don’t respond to the pharmacological therapy.