F10 and neoplasm: Thus, we hypothesized that increasing PS externalization to the outer cell surface of endothelial and tumor cells in the process of apoptosis induced by radiation can lead to a better pro-coagulant milieu and consecutively to a more efficient factor X (FX) activation at equimolar concentrations of tTF-NGR present in the membrane bound tTF-NGR:FVIIa:FX complex resulting in FX activation.