We panned them, along with a peripheral blood lymphocyte (PBL)-derived library from a single breast tumor patient, on living MCF7 breast carcinoma cells, as well as on three purified tumor surface antigens, i.e., CEA (carcinoembryonic antigen) [32], MUC1 (epithelial mucin) [33] and ED-B domain of fibronectin [34]. This evidence concerns the gene CEACAM5 and neoplasm.