CEACAM5 and neoplasm: As showed in Fig. 3a, epithelial tumor marker CA19-9 (>1000 vs. 2.86 U/ml, normal value: <39 U/ml) and AFP (65.85 vs. 0.20 ng/ml, normal value: <4.7 n/ml) levels in the culture supernatant were higher than those of pure growth medium (all P = 0.000); but CEA showed normal levels (0.61 vs. 0.61 ng/ml, P > 0.05; normal value: <7 ng/ml).