Figure 1.

Induction of protective antitumor immunity. Mice (10 mice in each group) were immunized i.m. with 100 μg of XVEGF-p (●), MVEGF-p (○), or c-p (■) or were nonimmunized (saline alone) (▴) once a week for 4 weeks. Mice were then challenged with 1 × 10⁶ Meth A cells (A) or H22 hepatoma (B) or MA 782/5S mammary cancer cells (C) s.c. 1 week after the fourth immunization. The results are expressed as mean ± SEM. Asterisks (*) indicate a significant difference in tumor volume (P < 0.05) between XVEGF-p-treated and control groups.