Epithelial-mesenchymal transition (EMT) is a developmental program implicated in cancer progression and was the subject of the 2010 AACR meeting on the topic of EMT and Cancer Progression and Treatment held on February 28 to March 2 in Arlington, Virginia. A review of the involvement of EMT in gastrulation, organogenesis, carcinogenesis, and metastatic progression elucidated the overlap of EMT in these physiologic and pathologic conditions. Both novel and traditional markers of cells undergoing EMT were discussed and compared with features used to define cancer stem cells. Importantly, these defining characteristics of cells undergoing EMT were discussed in the context of therapeutic and prognostic developments.