More than 90% of human cancer patients have subclinical haemostatic abnormalities with the majority of patients showing hypercoagulability associated with elevated fibrinogen levels, thrombocytosis, elevated levels of clotting factors V, VIII, IX and X and elevated levels of FDP, in addition to reduced levels of coagulation inhibitors (AT, Protein C and Protein S) and increased levels of plasminogen activator inhibitor-1 [1,5,31]. The gene discussed is PROS1; the disease is cancer.