VEGF blockade inhibits proliferation and induces cell cycle arrest of NSCLC cells. Cells were treated with neutralizing antibodies to VEGF (100 ng/ml, 1 μg/ml, 10 μg/ml) for 48 h. An IgG isotype control was used as a control for antibody specificity. Cell proliferation was measured using the BrdU assay (*p < 0.05, **p < 0.01, VEGF neutralizing antibody vs untreated, n = 3) (A). A549 and SKMES1 cells were treated with either recombinant VEGF (rVEGF), neutralizing antibodies to VEGF (Anti-VEGF), or both combined (A549 cells, *p < 0.05, rVEGF + anti-VEGF; *p < 0.01, untreated vs VEGF neutralizing antibody; **p < 0.001, untreated vs rVEGF, untreated vs rVEGF + Anti-VEGF, n = 3; SKMES1, *p < 0.05, rVEGF + anti-VEGF, *p < 0.01, untreated vs rVEGF; *p < 0.001, untreated vs Anti-VEGF, untreated vs rVEGF + Anti-VEGF, n = 3) (B). To examine the effect of VEGF on cell cycle distribution, NSCLC cells were treated with neutralizing antibodies to VEGF (10 μg/ml) for 48 h. Cell cycle analysis was carried out (n = 2) by propidium idodide staining and examined by FACS (C). Where indicated, data are expressed as the mean ± SEM from three independent experiments (n = 3). Statistical analysis was carried out by ANOVA using the Bonferroni multiple comparison post test.