TF and neoplasm: Because injecting tumor cells and apoptotic cells in separate veins reduces their effect on metastasis (Fig. 2C, D) and the effects of apoptotic cells are dependent on their ability to trigger coagulation through TF (Figs. 4 and 6), we postulate that tumor cells localized together in a clot with an apoptotic cell may be more likely to survive and form a metastatic nodule.