EPCAM and neoplasm: Further, available LBs29 intrinsically underestimate the number of CTCs in blood due to their antigen-based approach, which limits the count of positive events to the sole recognition of cells with epithelial receptors in their membrane (i.e., EpCAM),22 while mesenchymal, tumor stem cells or fluctuating phenotypic CTCs30,31 are completely disregarded.