Effects of Tan IIA on endothelial cells tube formation and TEC surface expression of growth factor receptors. (A, B) Tan IIA enhanced tube formation of HUVECs and human TECs (50×). (C) The percentage of VEGFR1- and PDGFR-positive TECs and the relative fluorescence intensities. Values were higher in the PR + Tan IIA group than NS group. *p<0.05, **p<0.01. (D) Tube formation was enhanced by Tan IIA in vivo, similar to results seen with Tan IIA incubation in vitro; the addition of the VEGFR1/PDGFR inhibitor SU6668 weakened this enhancement effect.