(A) Western blot to detect p-Y1175 VEGFR2, total VEGFR2, and β-actin in HDBECs stimulated with/without VEGF (10 ng/mL, 5 minutes). (B) Quantification of p-Y1175 VEGFR2 normalized to the total VEGFR2 (3 independent experiments). (C) Western blot to detect VEGFR2 in CD93 and IgG coimmunoprecipitated samples (CD93 Co-IP and IgG Co-IP) and flow-through samples (CD93 FT and IgG FT) derived from HDBEC protein lysates. (D) In situ PLA for CD93 and VEGFR2 in HDBECs. Scale bar: 25 μm. (E) Quantification of CD93-VEGFR2 interaction (green dots) relative to cell number (5 fields of view/sample). (F) In situ PLA for VE-PTP and VEGFR2 in HDBECs with/without VEGF (10 ng/mL, 5 minutes). Scale bars: 25 μm. (G) Quantification of VE-PTP–VEGFR2 interactions relative to cell number (4 fields of view/sample). **P ≤ 0.01; ***P < 0.001 by 1-way ANOVA with Dunnett’s multiple-comparison test. NS, not significant. Values represent mean ± SEM.