VEGFR2 expression levels in serum-free DMEM culture supernatants at different time points after transfection. Liposome and DNA were added in a 1:1 (w/w) ratio to HEK293 (seeding density 4 × 104 cells/well). Truncated-rVegfr2 indicates transfection of 0.15 μg of pCMV6-truncated-rVegfr2 DNA plus 0.10 μg pCMV-gfp/well. rVegfr2 indicates 0.15 μg of transfected DNA plus 0.10 μg pCMV-gfp/well. Control indicates transfection of 0.10 μg pCMV-gfp/well alone. rVegfr2: rat-Vegf-receptor2. *: P < 0.05.