NGP inhibits tumor growth in vivo. A) 4T1-NGP or 4T1-Vec cells (5×105) were injected into the fourth mammary fat pad of 6–7 wk old female Balb/c mice. Tumor volume was determined based on caliper measurements. Data represent mean ± se volume. P < 0.0001; 2-way ANOVA. B) Confirmation of NGP expression in primary tumors by RT-PCR. Lanes 1–4: 4T1-Vec; lanes 5–8: 4T1-NGP. Lanes 1, 3, 5, 7: NGP; lanes 2, 4, 6, 8: β-actin. NGP (NGP-V5) is indicated at 460 bp and β-actin at 380 bp.