“…Cytokeratins, a multigene family of proteins with differentiationassociated patterns of expression (Moll et al, 1982), have also been used to characterize neoplastic cells of epithelial origin in bone marrow (Lindemann et al 1992) and peripheral blood (Denis et al, 1997;Nakamori et al, 1997;Soeth et al, 1997). However, most of them are found in samples of healthy subjects, thus limiting their suitability as targets (Burchill et al, 1995).…”