Fig. (5) Tumor protection observed in immunized mice. The graph shows the percentage of tumor-free animals after being challenged with tumor cells. HLA-A2 (AAD) transgenic mice were immunized with either pcDNA3-CHI-E7p or pcDNA3-H-E7p, or injected with pcDNA empty vector. One week after the last immunization the mice were injected s.c. each with 5 x 10⁴ TC-1/A2 cells. Tumor growth was monitored by palpation every 3-4 days. The data shown are from one representative immunization experiment of two performed.