No apoptotic activity in the lungs of the immunized mice by the immunostaining for active caspase-3 and by TUNEL staining. Mice without tumor were immunized, and active caspase-3 was determined by staining the section of the lungs with an antibody reactive to mouse active caspase-3 (A-C), as described in “Materials and methods.” Apoptotic cells in the lungs of the mice were also estimated with TUNEL assay (D-F). No apoptotic activity was found by immunostaining active caspase-3 or by TUNEL staining. (A,D) Immunization with qVEGFR. (B,E) Immunization with mVEGFR. (C,F) Nonimmunization. In addition, qVEGFR-immunized mice (A,D) did not show the alveolar enlargement compared with control groups. Original magnification is ×200 for all panels.