EPCAM and Merkel cell skin cancer: We detected MCC cells in these blood samples using the CellSearch system (an EpCAM-positive enrichment method based on magnetic beads selection combined with an immunocytochemical staining to identify CTCs), and the new workflow that combines RosetteSep for negative enrichment, by forming a network of unwanted blood cells discarded after blood centrifugation on a density medium, combine with the DEPArray, a dielectrophoresis technology allowing visual selection and single cell sorting, for cell identification.