Transfection efficiencies and apoptotic indices of the pCMV6-rVegfr2- and pCMV6-truncated-rVegfr2- HEK293 cells. HEK293 cells were co-transfected with pCMV-gfp (0.10 μg/well) and pCMV6-rVegfr 2 or pCMV6-truncated-rVegfr2 plasmids (4 × 104cells/well). PI and Hoechst staining were performed at 72 h after transfection in each experimental group. A, Control group (transfected with pCMV-gfp plasmid only). B-D, transfected pCMV6-truncated-rVegfr2 plasmid with three different concentrations. E-G, the concentrations of transfected pCMV6-rVegfr2 plasmid with three different concentrations. rVegfr2: rat-Vegf-receptor2. Scale bar: 1000 um.