The circulating epithelial tumour cells (CETCs) were quantified before and after separation of analogous to the maintrac method [2], i.e., leukocytes containing tumour cells were prepared by erythrocyte lysis, labelled with fluorescence markers (Anti-Epithelial Cell Adhesion Molecule (EpCAM) and CD45) and analysed by a laser scanning cytometer (LSC CompuCyte, Cambridge MA, USA). The gene discussed is EPCAM; the disease is neoplasm.