One of the difficulties for preventing the evolution of a tumor is that cancer progression can be promoted by undifferentiated or migrating cells whose states could follow different directions. At the 40th edition of Barcelona Biomed conferences at the Institute for Research in Biomedicine (IRB Barcelona), which took place from Nov. 27 to 29, 2023, and is entitled “Cancer in Context: Cellular, Tissue, and Organismal Determinants of Malignant Fates,” Angela Nieto presented her latest data on epithelial-to-mesenchymal transition (EMT).