Heterogenous coagulant profiles associated with glioma. (A) Immunodetection (ELISA) of circulating human PDPN in plasma of mice with U373PT and U373vIII glioma xenografts. Suppression of PDPN in EGFRvIII-driven U373vIII cells leads to low PDPN levels in blood (Control - plasma of tumor-free mice). Tumor sizes were comparable across the entire panel (supplemental Information). (B) Detection of various PDPN levels in plasma of GBM patients (human PDPN ELISA), mostly above the normal levels of 1.31 ± 0.13 ng of PDPN protein per mL of plasma as reported in the literature.⁴⁷  (C) Reduced platelet counts in mice harboring PDPN^high glioma xenografts (U373PT, U373TF-G11-PT) vs PDPN^low tumors (U373vIII) and tumor-free controls (no myelosuppression was observed; supplemental Information). (D) Increased PF4 levels in plasma of mice with PDPN^high glioma xenografts vs those with PDPN^low tumors and controls (as in panel C). (E) D-dimer levels in plasma of mice bearing glioma xenografts. In the case of tumors expressing PDPN (U373PT), D-dimers were not significantly different from those in controls; however, they were elevated in TF-expressing U373vIII tumors and U373TF-G11-PT tumors with high levels of TF and PDPN. (F) PF4 levels in plasma of mice injected IV with glioma EVs (10 μg per mouse). PF4 elevation occurred in mice injected with PDPN-carrying EVs (U373TF-G11-PT and U373PT) regardless of TF status, whereas PDPN⁻ and TF⁺ EVs (U373vIII) did not produce any such increase above the background (phosphate-buffered saline). *P ≤ .05, **P ≤ .01, ***P ≤ .001, ANOVA multiple-comparison analysis. ns, not significant.