Gordon Research Conference on Circulating Tumor Cells and Metastasis. August 3-8, 2014. Mount Holyoake College, MA. . Epithelial progenitor and stem cells, mesenchymal cells, fetal cells, and circulating tumor cells are normally relegated to extravascular organs but can traffic within the blood stream to initiate a number of important biological processes, such as organ repair and regeneration, angiogenesis, and metastasis. This conference will bring together engineers, biologists, and clinicians to address the wide range of interest in these rare cell populations, particularly cancer-relevant cells.