Oncogenic status of tumors influences circulating TF levels. (A) Circulating TF is detectable in the plasma of HCT116 tumor-bearing mice, and plasma TF concentration is proportional to tumor volume. Asterisked points were excluded from the linear regression. (B) Higher plasma TF concentrations are observed in mice with tumors originating from the p53^-/- variant of HCT116 cells (379.2 cells), relative to those with HCT116 tumors of a similar size. The TF ELISA detects human (but not mouse) TF. Tumor volume (mean ± SD) for each group is indicated. (C) The cell-free TF activity produced by HCT116 and sublines is associated with pelleted membrane vesicles after ultracentrifugation. Error bars indicate standard deviation.