Induction of therapeutic anti-tumor immunity. Mice (five per group in both the CT26 and 4T1 tumor models) were treated i.v. once a week for 6 weeks with 20 μg of pORF-hFlk-1 LDC, pORF-mFlk-1 LDC, pORF-mcs LDC alone or GS. Treatment was started 13 days after 2 × 105 CT26 cells were subcutaneously administered to the mice, (A, C) or 4 days after they received 8 × 105 4T1 tumor cells (B, D). Data are expressed as means ± SEM. A significant increase in survival in human VEGFR-2 LDC-treated mice, compared with the control groups (P < 0.01, by log-rank test), was found in both tumor models.