However, because the radioactivity concentration in the normal tissues was reduced to a even greater extent, the tumor-to-blood and tumor-to-liver ratios were 10.6 and 2.2 respectively for the pretargeting group, significantly higher than those for the 111In-labeled anti-CEA antibody (1.5 and 0.5 respectively). This evidence concerns the gene CEACAM5 and neoplasm.