As expected, our quantitative RT-PCR assays using primers specific for human NRP-1 and VEGFR-2 failed to detect both NRP-1 and VEGFR-2 in the peritumoral tissue while RT-PCR assays using primers specific for mouse NRP-1 and VEGFR-2 showed a time dependent decrease in both NRP-1(p = 0.013) and VEGFR-2 (p = 0.023)in the peritumoral tissue (Fig. 4B and 4C), indicating that tumor growth impacted on the expression of NRP-1 and VEGFR-2 in the peritumoral hepatic tissue. This evidence concerns the gene KDR and neoplasm.