In vivo VEGF165 gene and protein levels. (a) VEGF165 protein levels in the peripheral blood, as assessed by ELISA. (b) VEGF165 gene expression in the penis 21 days after EPC transplantation as assessed by RT-PCR. Bands from the trial group (I), blank-plasmid group (II) and control group (III) all appeared to be between 500 and 700 bp in length, but the band that belonged to the trial group was brighter than those of the other groups. M, DNA marker. *P<0.05, compared with blank-plasmid group and control group. EPC, endothelial progenitor cell; VEGF, vascular endothelial growth factor.