TF and neoplasm: The conflicting data may result from the fact that in tumor cells expressing both receptors the final biological effects depends on reciprocal interaction influenced by a variety of ligands and cofactors like PC and its inhibitor (PCI), plasminogen activator inhibitor (PAI)-1, thrombin, thrombomodulin (TM), sphingosine 1 and 3 phosphate receptor S1P1, S1P3 and procoagulants, e.g., tissue factor (TF) [13].