Briefly, the formation of thrombin in a plasma sample is continuously measured by a fluorogenic substrate after initiation of coagulation, typically by tissue factor (TF) in the presence of calcium and phospholipids.7The assay has shown to be able to detect thrombophilia both due to inherited and acquired causes.8, 9, 10In TG, endless assay condition variations can be made, affecting the performance of the test to detect hypercoagulable states. Here, TF is linked to Rare hereditary thrombophilia.