Direct immunization with LV-huCEA induces huCEA-expressing tumor stabilization. In this representative experiment, huCEA Tg mice were injected s.c. with mGC4CEA cells in the flank. Mice were then directly vaccinated with PBS (5 mice; empty squares), LV-huCEA (6 mice; filled circles), or LV-enGFP (5 mice; empty diamonds). Tumors were measured over time using a caliper. *, P < 0.005, compared with PBS and LV-enGFP controls.